Content Accessibility

Office Documents

This section focuses on office formats that were designed to be edited and which are often used as a source for other web content, either PDF or (less commonly) HTML. In such scenarios, the source format needs to be made as accessible as possible before exporting or saving the content in different target format.

General Resources

Guidance for multiple applications or office suites.

• Creating accessible documents, AG Services Disability and Studies (AGSBS), Technische Universität Dresden, last updated on 14.08.2020.
  See especially the section “Instructions for barrier-free design of documents via Microsoft Word and PowerPoint”, where you can download PDF files with instructions for Microsoft Word 2016, Microsoft PowerPoint 2016, Microsoft Word 2019 and Microsoft PowerPoint 2019.
• Microsoft in Government: Creating Accessible Documents: YouTube playlist consisting of 10 short videos. The videos cover the following topics: document naming, headings and styles, lists, columns, tables, languages, links, alt text, and joining the accessibility community.
  See also Accessibility in Microsoft Office 2010 and Accessibility in Microsoft Office 2013 on the Microsoft Accessibility website.
• Accessible Digital Office Document (ADOD) Project: Accessibility of Office Documents and Office Applications: website with authoring techniques for Microsoft Word, Google Docs, iWork Pages, LibreOffice Writer, Microsoft Excel, OpenOffice Calc, Microsoft PowerPoint, OpenOffice Impress and several other applications.
• The 10 TVS Guidelines For Making Your Documents Braille-Ready, Techno-Vision Systems Ltd. (no date).
• PDFs und Co: Dokumente barrierefrei veröffentlichen, Der Landesbehindertenbeauftragte der Freien Hansestadt Bremen (no date; accessed on 26.02.2021).
• Guidance: Accessible communication formats, Gov.UK, updated on 15.03.2021.
• Microsoft: Use the Accessibility Checker on your Windows desktop to find accessibility issues (this applies to all versions of Microsoft Office for Windows since version 2010) & Use the Accessibility Checker on your Mac to find and resolve accessibility issues.
• Lay-Flurrie, Jenny: Microsoft’s Accessibility Journey: Education, Work and Life, Microsoft Accessibility Blog, 19.03.2018. Quote: We moved the Accessibility Checker to the ribbon and usage increased 5 times.
• Comment créer des documents accessibles, Boîte à outils d'accessibilité numérique - Gouvernement du Canada, 2010.
• Barrierefreie Grafik-Gestaltung für Print und Digital, Barrierefreiheit | Schulung, Begleitung und Tests (no date; accessed on 12.04.2022). Also discusses the question Gibt es die barrierefreie Schrift?

Microsoft Word

• Make your Word documents accessible to people with disabilities, Microsoft Office Support (accessed on 18.06.2021).
  Microsoft's support documents are also available in other languages (often generated using translation software). For example, the guidance on accessible Word documents is available in German as Gestalten barrierefreier Word-Dokumente für Personen mit Behinderungen.
• Microsoft Word: Creating Accessible Documents, WebAIM, last updated on 26.02.2021.
• Microsoft Office Word, Zweiter Blick (no date, accessed on 16.06.2021).
  This article covers Microsoft Word versions 2010–2016.
• Making Word Processing Documents Accessible, Lexdis, 11.04.2017, updated on 04.03.2020 (accessed on 16.06.2021).
  This is a list of tips that can be read in a few minutes. (The advice about saving as RTF is outdated.)
• Thompson, Terrill: Converting Word to PDF or HTML: Options for Accessibility, Terrill Thompson's blog, 30.06.2014.
  This blog post is now a bit old; since 2014, Microsoft Word 2016 and several new versions of LibreOffice have been released.
• Thompson, Terrill: Alt Text in Word: Title vs Description, Terrill Thompson's blog, 11.07.2014.
  The word processing programs discussed in this blog post Word 2013 and other programs that were available in July 2014. Since accessibility support has evolved considerable since 2014, the blog post should be considered as historical information only.
• Documents Word accessibles, Technologie, Handicap, Accessibilité, last updated on 19.07.2015.
• Caprette, Heather: Creating Accessible Word Documents , Best Practices in Accessible Online Design (no date; accessed on 03.07.2022; Creative Commons).
• Brauner, Diane: Creating an Accessible Table in Word, Perkins School for the Blind, 03.03.2017.
• Creating Accessible Tables in Microsoft Word, EASI: Equal Access to Software and Information (no date; accessed on 08.07.2021).
  This guide is based on Word 2003 and Word 2010 and is therefore partially outdated.
• Creating Accessible Documents in Microsoft Word, University of Washington (no date; accessed on 17.11.2021. (This document covers only a small subset of what authors need to consider.)
• Berman, David: How To: Alternative Text for Decorative Images in any version of Microsoft Office, David Berman Communications, 01.11.2020.
• Wie lesen blinde Menschen? Dokumente barrierefrei erstellen. (Universitätsbibliothek der Justus-Liebig-Universität Gießen on YouTube, 22 minutes, 25.06.2021; Creative Commons licence).
  This video contains a brief introduction to digital accessibility, followed by a presentation on accessible Word documents by Steffen Puhl. Puhl is blind, so he knows the topic first hand.
• Screen Reader User's Experience and MS Word (Assistive Technology Showcase on YouTube, 4 minutes, 02.05.2014).
  This video shows how JAWS reads an accessible and an inaccessible version of the same document, focusing on headings, images and links. (Lists are not demonstrated.)
• Hörbeispiel: Vorlesen eines barrierefreien Dokuments mit Screenreader (www.netz-barrierefrei.de on YouTube, 2 minutes, 24.10.2020).
  Description below the video: In diesem Video hören Sie, wie ein Screenreader ein typisches einfaches mit Word barrierefrei gemachtes PDF vorliest. Es kommen vor Überschriften, Listen, ein Bild mit Beschreibung, eine Tabelle und ein Sprachwechsel.
  Eingesetzt wird der kostenlose Screenreader NVDA und die Sprachausgabe eSpeak.

Word's feature for inserting videos (under Insert, then Online video) does not really insert a video into a Word document, but creates a thumbnail that looks like it has a Play button on it and that acts as a hyperlink to the online video. The video can only be played if you are online while reading the document.

Microsoft Word Forms

• Page, Ted: You can't make Microsoft Word forms accessible (enough) …, Accessible Digital Documents, 29.09.2019.
• Creating accessible forms in MS Word (PC version) (Adrian Cooke on YouTube, 24 minutes, 12.03.2021).
  This tutorial explains a number of accessibility practices that are not related to fields (for example, heading styles and the heading hierarchy in the Navigation pane) before moving on to forms as such (alsmost 10 minutes into the video). Forms are created using legacy fields. Fields are given a name (under “Bookmark”) using a camel-case version of the visual label. The “Status Bar text” is what will become visible on the status bar when a field receives focus and gets read out by a screen reader. The content of the “Status Bar text” is based on the visible label. (For the field with the visual label “Email”, the author chooses “Your College email” as Status Bar text. It is not clear, why the visible label is not more specific. Similarly, 20 minutes into the video, a large text field is given the visible label “Describe your project” and the Status Bar text “Provide a paragraph that describes your project”.) Almost 21 minutes into the video, the author shows how to create a style for a text area (as opposed to a short text input field. The video does not explain how to make sure that headings and instructions are read out when a screen reader users fills in the form in protected mode.
• Word 2013 & 2016: Creating Accessible Word Forms (Governors Committee on People with Disabilities on YouTube, 10 minutes, 08.11.2016).
  This short tutorial recommends using the legacy form tools. It recommends renaming a field's “Bookmark” to a camel-case version of the visual form field label. The “Status Bar text” becomes visible in the status bar [when the document is tabbed through in protected mode] and is spoke by JAWS. The length of the field is limited to 128 characters. Abbreviations should be spelled out, for example, “date of birth” for “date of birth”.
  In a drop-down list, the first option becomes the default value, so it may make sense to set “Pick one” as the first value JAWS will say “has F1 Key help” if a field has associated help text (i.e. after reading the status bar text). The length of this help text is limited to 254 characters; this text should only be used if the help text prompt is not clear by itself. Forms also contain instructions. To make sure these are read out, the video recommends inserting a checkbox after the instructions, reducing its size to 1pt and setting help text for that checkbox (i.e. “Info” followed by the text of the visual instructions (shortened if necessary). In some cases, more than one checkbox may be needed.
  The status bar text for the last form field should contain the words “End of form”. Otherwise, screen reader users will hit the Tab key and return to the top of the form. As a last step, the form can be locked to protect it, allowing only filling in the form.
• Creating Accessible Microsoft Word 2010 Documents: Word Forms (Governors Committee on People with Disabilities on YouTube, 6 minutes, 10.08.2012).
  This short tutorial dates from 2012 and is therefore partially outdated. It recommends using Word's legacy form controls (in a table layout) and points out that ActiveX controls and Content Controls don't work properly with assistive technologies. ZoomText does not always track Word checkboxes, forms with columns do not tab properly in a protected form, and radio buttons and other form elements may not work correctly with various assistive technologies.
  The video gives recommendations on the “Status Bar text”, which should begin with the word “Info:” and match the visual prompt. In addition, the “Status Bar text” should contain the phrase “end of form”.
• Creating Accessible Forms in Microsoft Word, Freedom Scientific, updated on 25.04.2013 (accessed on 06.07.2021).
  This document was last updated in 2013. It contains the following note: There are several new form controls called "content controls" that are available in Word 2007 - 2013 for creating form fields. At the present time, JAWS does not work with forms created with the newer content controls. Microsoft is aware of this and they are working towards a better solution. Therefore, these instructions show you how to use legacy controls within Word to create accessible forms. (The issue is also mentioned in the 2011 version of “Creating Accessible Forms in Microsoft Word”.)
• Making Fillable Forms Accessible for Screen Readers, Microsoft Community, 03.01.2019.
  See especially the answer by KarenMcCall1 (08.01.2019).
• Create forms that users complete or print in Word, Microsoft Support (no date; accessed on 30.12.2021). This document ignores accessibility.

Microsoft PowerPoint

• Make your PowerPoint presentations accessible to people with disabilities, Microsoft Office Support (accessed on 18.06.2021).
  Microsoft's support documents are also available in other languages (often generated using translation software). For example, the guidance on accessible PowerPoint presentations is available in German as Gestalten barrierefreier PowerPoint-Präsentationen für Personen mit Behinderungen.
• Change the color of hyperlink text throughout a presentation, Microsoft Office Support (accessed on 24.06.2021).
• Accessibility features in video playback on PowerPoint, Microsoft Office Support (accessed on 24.06.2021).
• Add closed captions or subtitles to media in PowerPoint, Microsoft Office Support (accessed on 24.06.2021).
  German translation: Hinzufügen von Untertiteln zu Medien in PowerPoint.
• Make slides easier to read by using the Reading Order pane, Microsoft Office Support (accessed on 24.06.2021).
• Video: Erstellen von barrierefreieren Folien, Microsoft Office Support (accessed on 24.06.2021).
• Creating Accessible PowerPoint Presentations (UA Technology Accessibility on YouTube, 53 minutes, 14.07.2018).
  Webinar taught by Melissa Green.
• How to check the reading order in PowerPoint presentations (Wolf Helping Hand on YouTube, 5 minutes, 29.11.2019).
  This video demonstrates checking reading order in PowerPoint 2019 (or PowerPoint 2016?): on the Home tab, go to the Drawing group and choose “Arrange”, the “Selection Pane”. In this PowerPoint version, the order goes from the bottom to the top, as in PowerPoint 2016.
• Create Accessible MS PowerPoint 2019 Presentations, University of Central Oklahoma Service Desk, 07.05.2020, updated on 07.05.2021.
  With regard to the reading order for objects on a slide, this page says, The reading order in the Selection Pane is read bottom to top. The element at the bottom of the reading order will be read first. The title of the slide should always be read first. (In Office 365, the order is top to bottom.)
• PowerPoint Accessibility, WebAIM, last updated in March 2018.
• Veroniiiica: How to Create Accessible PowerPoints, Perkins eLearning blog, 25.10.2017.
• Callahan, Shawn: Why you should avoid having text on your slides when you are talking, Anecdote, 29.03.2019.
• Selecting multiple objects in PowerPoint (In-Process 19th November 2021), NV Access, 19.11.2021.

Other Microsoft Applications

• Accessible Office Templates, Microsoft (no date; accessed on 22.10.2021).
  Templates for Word and Excel (but not PowerPoint).
• Create accessible Office documents, Microsoft Office Support (accessed on 18.06.2021).
• Office Accessibility Center - Resources for people with disabilities, Microsoft Office Support (accessed on 18.06.2021).
• Make your Excel documents accessible to people with disabilities, Microsoft Office Support (accessed on 18.06.2021).
• Microsoft: Accessibility support for Visio: this document covers Visio Professional 2016 and more recent versions.
• Steinberg, Richard: Accessible Microsoft Office: Excel 2016/365, AccessU2019 (GitHub Pages) (no date; accessed on 27.10.2021).

LibreOffice

Information on creating accessible content using LibreOffice is relatively scarce compared to the volume of information on accessibility in Microsoft Office and Adobe Acrobat. It is also less detailed and less up to date.

• How to Create Accessible LibreOffice files, Document Foundation Wiki (Creative Commons Attribution-ShareAlike 3.0 Unported License).
  This wiki page is still based on LibreOffice 5.2, which was released in August 2016.
• Accessibility, LibreOffice Get Help (no date; accessed on 10.04.2022). (German translation: Barrierefreiheit.)
  This page documents accessibility features of the LibreOffice interface rather than accessible authoring practices.
• Authoring Techniques for Accessible Office Documents: OpenOffice Writer (v3.4) and LibreOffice Writer (v4.0.4.2), Accessible Digital Office Document (ADOD) Project, last updated on 19.07.2013 (and outdated by newer versions of LibreOffice).
• Authoring Techniques for Accessible Office Documents: OpenOffice Impress (v3.2), Accessible Digital Office Document (ADOD) Project, last updated on 04.02.2011 (and outdated by newer versions of LibreOffice).
• Introducing the accessibility sidebar - LibreOffice Conference 2023 (LibreOffice - The Document Foundation on YouTube, 4:46 minutes, 03.10.2023; Creative Commons licence).
  Presentation and demo by Samuel Mehrbrodt at the LibreOffice conference in Bucharest on 22.09.2023.
• Barrierefreie Dokumente mit Libre Office (www.netz-barrierefrei.de on YouTube, 18 minutes, 21.07.2021).
• Ausfüllbare PDF-Formulare erstellen – mit Acrobat und Freeware, IONOS, 11.08.2020 (accessed on 15.07.2021).
  This article only discusses how to create PDF forms, not how to make them accessible.
• Universal Accessibility (PDF/UA), LibreOffice 7.1 Help (no date; accessed on 10.08.2021).
  See also Bug 135196 - PDF export: Universal Accessibility not documented (reported in July 2020).
• Accessibility Check, LibreOffice 7.3 Help (accessed on 24.05.2022).
  This help page lists the checks implemented in the accessibility checker. The checker is invoked automatically when authors export a Writer document to PDF/UA. This checker will be improved in future versions of LibreOffice Writer.
• Rodrigues, Marc: Collabora Online 21.11.2.4 Brings Accessibility Checker and Improved UX, Collabora Office and Collabora Online, 04.03.2022.
• Universal Accessibility (PDF/UA), LibreOffice 7.3 Help (accessed on 24.05.2022).
  This help page lists the checks implemented in the accessibility checker (status of January 2020). The page still mentions Web Content Accessibility Guidelines (WCAG) 2.0 instead of version 2.1, which was released in June 2018.
• Accessibility Check, LibreOfficeDev 7.4 Help (accessed on 24.05.2022, when LibreOffice 7.4 was still in developement).
• Vajngerl, Tomaž: Accessibility checker and support for PDF/UA specs, Tomaz's dev blog, 22.01.2020.
• ODF Validator: a service maintained by The Document Foundation. This is an ODF conformance checker, not an accessibility checker.
• AccessODF: a Java-based extension for LibreOffice or OpenOffice.org 3.3 that checks the accessibility of Writer documents (essentially any word processing format supported by Writer). It was developed in 2008—2011 and is not compatible with current versions of LibreOffice or OpenOffice.org (any version higher than 3.4). This checker is being replaced by one that is built into LibreOffice; see the blogpost by Tomaž Vajngerl, above.
  See also the document Mapping AccessODF Checks to Web Content Accessibility Guidelines (WCAG) 2.0

LibreOffice Accessibility Issues

LibreOffice still has a number of accessibility issues when saving or exporting to other formats. A number of bugs have been reported; see for example the following metabugs: Bug 101912 (a11y) - [META] Accessibility (a11y) bugs and enhancements (some of these bugs are about the user interface rather than file formats) and Bug 139007 (PDF-Accessibility) - [META] PDF accessibility. Not all accessibility issues are linked to relevant meta bugs, for example, Bug 139736 - Images and frames in header violate PDF/UA (reported in January 2021).

LibreOffice Impress does not support captions or subtitles in videos. (According to What video formats does LibreOffice Impress support? from March 2012, the video formats supported by LibreOffice depend on platform-dependent multimedia frameworks installed on the operating system on which one uses LibreOffice. On Windows, this depends on Supported Formats in DirectShow (2008), on Linux, this depends on the formats supported by gstreamer, on Mac, this depends on the media formats supported by QuickTime Player (November 2014). See also Audio or Video in LibreOffice 7.0 Help.

ODF and PDF Forms Created Using LibreOffice

Forms created in LibreOffice Writer or OpenOffice Writer can be exported to PDF forms; one only needs to activate the checkbox “Create PDF form” in the “PDF Options” dialog box. There are no resources that discuss the accessibility of forms created in Writer or exported as PDF from Writer. However, when testing PDF forms generated by LibreOffice Writer 7 with NVDA in July 2021, the screen reader does not read the form fields. In addition, when an ODF form has been saved in read-only mode, the form fields are not accessible using only the keyboard.

• Chapter 18: Forms (Writer Guide 7.1), LibreOffice Community, April 2021.
  This guide is based on LibreOffice 7.1. It does not mention accessibility; for example, it does not discuss the relationship between labels and accessibility, nor how forms can be filled in using only the keyboard.
• Form Navigator, LibreOffice 7.1 Help (accessed on 10.08.2021).
  No information related to accessibility.
• Form Controls (LibreOffice 7.1 Help), LibreOffice 7.1 Help (accessed on 10.08.2021).
• Bug 85339 - FORMCONTROLS: Tabindex is ignored for fields with the same name, The Document Foundation Bugzilla, reported on 22.10.2014.
• Bug 108687 - Form option buttons not reachable with tab key, The Document Foundation Bugzilla, reported on 22.06.2017.
• Bug 143818 - Writer form fields are not accessible using only the keyboard [accessibility], The Document Foundation Bugzilla, reported on 10.08.2021.

OpenDocument Format (ODF)

The OpenDocument Format is maintained as an open format by the OASIS Open Document Format for Office Applications Technical Committee. This committee released version 1.3 of the format in June 2021; see OpenDocument V1.3 OASIS Standard published (OASIS, 16 June 2021) and ODF 1.3 is an OASIS Standard (The Document Foundation, 23.06.2021). The OpenDocument - Accessibility Subcommittee was closed 11 February 2020 and is no longer active. OpenDocument 1.2 was also published as an ISO standard; see ISO/IEC 26300-1:2015: Information technology — Open Document Format for Office Applications (OpenDocument) v1.2 — Part 1: OpenDocument Schema. This standard was last reviewed and confirmed in 2020 and was still the current standard when OASIS released OpenDocument version 1.3 in June 2021.

• Open Document Format for Office Applications (OpenDocument) Version 1.3. Part 1: Introduction, OASIS Standard, 27 April 2021. OASIS Open, 2021.
• Open Document Format for Office Applications (OpenDocument) Version 1.3. Part 2: Packages, OASIS Standard, 27 April 2021. OASIS Open, 2021.
• Open Document Format for Office Applications (OpenDocument) Version 1.3. Part 3: OpenDocument Schema, OASIS Standard, 27 April 2021. OASIS Open, 2021.
  This is the part of the standard where the elements and attibutes that make up a document's visible content (and their text alternatives and other properties) are defined.
• Open Document Format for Office Applications (OpenDocument) Version 1.3. Part 4: Recalculated Formula (OpenFormula) Format, OASIS Standard, 27 April 2021. OASIS Open, 2021.
• XML/RNG schemas and OWL ontologies, OASIS Standard, 27 April 2021. OASIS Open, 2021.
• Open Document Format v1.1 Accessibility Guidelines Version 1.0, Committee Specification 01. OASIS Open, 01.05.2008.
  These guidelines were written by Peter Korn (Sun Microsystems, later Oracle) and Rich Schwerdtfeger, IBM. The guidelines state they apply to the OASIS OpenDocument v1.1 specification.
• OASIS Open Document Format for Office Applications (OpenDocument) TC Issue Tracker.
• Archive for the mailing list office-comment: public mailing lists for the submission of comments on the ODF specification.
• OASIS Open Document Format for Office Applications (OpenDocument) Technical Committee, OASIS Open. This charter was last updated in May 2021.
• Updegrove, Andy: Showing the Accessibility Way: IBM Contributes Project Missouri to the Free Standards Group, ConsortiumInfo.org, 14.12.2006.
  This article is now only of historic interest. It is about accessibility improvements in both ODF and ODF applications. This includes the accessibility API iAccessible2, which complements Microsoft Active Accessibility (MSAA).

Other Applications (Including Google Docs)

• How to Create Accessible Presentations with Google Slides, Stanford Office of Digital Accessibility, Stanford University (no date, accessed 16.02.2021).
• How to Check the Accessibility of Your Google Slides (Richard Byrne on YouTube, 3 minutes, 29.07.2020).
  This video demonstrates Grackle Slides, an add-on for Google Slides that can check the accessibility of presentation slides.
• An Overview of Google Docs Accessibility Options (Richard Byrne on YouTube, 5 minutes, 20.12.2019).
• Accessibility for Google Docs, Sheets, Slides, & Drawings, Google Docs Editors Help (no date; accessed on 22.10.2022).
  (Before using Google Docs, Sheets or Slides, you should turn on screen reader support.)

Portable Document Format (PDF)

Warning: “tagged PDF” is lipstick on a pig.

• Adobe: Adobe Acrobat Accessibility.
• Adobe: Adobe Acrobat Accessibility: Training Resources.
• Creating accessible PDFs, Adobe (accessed on 24.06.2021).
• Create and verify PDF accessibility (Acrobat Pro), Adobe, last updated on 24.05.2023.
  (An older version of this document, accessed in November 2021, claimed that The Full Check/Accessibility Check tool verifies whether the document conforms to accessibility standards, such as PDF/UA and WCAG 2.0. This claim was later removed.) The document contains a mapping between WCAG 2.0 and PDF/UA (ISO 14289-1).
• PDF Accessibility Overview, Adobe (no date; accessed on 05.11.2021).
• Haverty, Rob: Accessibility in Acrobat DC: Ensure the Accuracy of a Tagged PDF, Adobe Blog, 10.01.2018.
• Castro, Dax: PDF Accessibility for ADA Compliance, Adobe (no date; accessed on 05.11.2021).
• Barrierefreie PDF-Dokumente erstellen, Adobe, last updated on 30.04.2021 (accessed on 24.06.2021).
• The Matterhorn Protocol 1.1, PDF Association, 2.04.2021.
  The PDF Association describes the Matterhorn Protocol 1.1 as follows: To promote adoption of PDF/UA - the ISO standard for accessible PDF - by software developers, service bureaus and those interested in document accessibility, the PDF Association's PDF/UA Technical Working Group has developed the Matterhorn Protocol, a list of all the possible ways to fail PDF/UA-1.
  The 1.1 release of the Matterhorn Protocol, released in April 2021, adds a new failure condition and provides several clarifications. The PDF file is tagged to reflect current best-practice in tagging PDF documents for accessibility and reuse.
• PDF Accessibility: Defining Acrobat PDF Accessibility, WebAIM, last updated on 31.05.2023.
• Metzessible PDF/UA Series: YouTube playlist about accessible PDF. PDF/UA is the informal name for ISO 14289.
• MSFTEnable: PDF Accessibility (YouTube, January 2019). This is a playlist containing of 10 videos that are between two and four minutes long. See for example PDF Accessibility: Tagged PDF (YouTube, 2 minutes, 28.01.2019) and PDF Accessibility: Images (YouTube, 2 minutes, 28.01.2019).
• Creating Accessible PDF files (Points of Access with Philip White on YouTube, 2019): this is a YouTube playlist containing videos on topics such as editing OCR done in Adobe Acrobat, tagging PDF and basic accessibility checking.
• Adobe Acrobat Accessibility series (Points of Access with Philip White on YouTube, 2019).
• Rivenburgh, Chris: The PDF Accessibility Guide: How to Make Your Portable Documents Accessible, Medium, 17.06.2019.
• Ashish Tiwari: Using Auto-Tagging To Achieve PDF Accessibility: Expectations vs Reality (White Paper), CommonLook, 14.10.2020.
• Barrierefreies PDF. (Website by Stefan Brechbühl from Switzerland. Licence: Creative Commons Attribution 4.0 International.)
• Wallis, Sean: PDF Accessibility for Web Developers, Enrise, 03.06.2019.
• Frölich, Dirk: Barrierefreie Tabellen in PDF-Dokumenten, Barrierefreie Tabellen in PDF-Dokumenten, Teil 2, Barrierefreie Tabellen in PDF-Dokumenten, Teil 3, blog.df-edv, 23.03.2018, 16.04.2018, 24.04.2018 (respectively).
• PDF Barrierefreiheit: German blog about PDF accessibility.
• University of Washington: Fixing Inaccessible PDFs Using Adobe Acrobat Pro DC (no date).
• Faulkner, Steve: An overview of PDF inaccessibility, TPGi blog, 17.02.2017.
  See also Mike Gifford's comment (dated 29.05.2017): I’ve been calling for people to abandon PDF and move to EPUB for years. I’ve met some resistance from people in the PDF world, but haven’t heard any resistance from people with disabilities.
  Craig Francis has called for a different type of alternative: PDF Alternative Using HTML (ZIP/GZIP)
• Bundesfachstelle Barrierefreiheit: Barrierefreie PDF (no date). This is a collection of links to resources in German.
• Posselt, Klaas: Barrierefreie PDFs und der Umfließen-Modus – ein leidiges Thema, *einmanncombo, 29.07.2019.
• PDF Accessibility - Fixing tags and reading order (Nicki Berry on YouTube, 9 minutes, 17.07.2021).
  Demonstrates various types of repairs, such as deleting empty tags, setting a text alternative for an iamge, correcting tag type for a figure and moving tags in the tag tree.
• Kassuba, Lori: How to create structured bookmarks using Acrobat XI, Acrobat forum, 07.01.2014.
• Campbell, Alastair: PDF vs HTML for organisations, AlastairC, 05.01.2011.
• PDFs and Accessibility, Claro Software Support, 27.03.2012.
• Posselt, Klaas; Frölich, Dirk: Barrierefreie PDF-Dokumente erstellen. dpunkt.verlag, 2019. (614 pages) ISBN 978-3-86490-487-5. This book covers PDF accessibility in Adobe InDesign, Microsoft Office and LibreOffice. Accompanying website: barrierefrei-publizieren.de.
  German review: Buchbesprechung – „Barrierefreie PDF-Dokumente erstellen“ von Klaas Posselt und Dirk Frölich by Kerstin Probiesch (04.07.2019). The book appears to have serious shortcomings.
• Gillen, Mary: How to Fix 40 Common PDF Accessibility Errors, <accessible-website-services>, 26.09.2020. (The PDF file that contains the information costs USD 25.)
• Example of Using a Screen Reader with an Accessible PDF (Lauren Alcorn on YouTube, 2 minutes, 06.04.2016).
• Making Accessible Word Documents Accessible PDFs (Adam Barragato on YouTube, 3 minutes, 21.09.2017).
• PDF 508 Accessibility Checklist, Social Security Administration, 12.03.2018.
• Rivenburgh, Kris: The PDF Accessibility Guide: How to Make Your Portable Documents Accessible, Kris Rivenburgh (on Medium), 17.06.2019.
• Texas Commission on Environmental Quality (TCEQ):
  1. Unit 1 – Getting Started with Adobe Acrobat: playlist containing 3 videos, including two videos about PDF forms.
  2. Unit 2 – Making an Accessible PDF: playlist containing 14 videos, including the following: Designating PDF Artifacts (TCEQNews on YouTube, 9 minutes, 15.07.2021; accessed on 05.08.2021).
  3. Unit 3 – Testing PDF Accessibility: playlist containing 9 videos.
• Web Accessibility 101: Screen Magnification & Reflow in Adobe Acrobat (Level Access on YouTube, 2 minutes, 14.01.2014).
• Header and footer artifacts (Tagged PDF on YouTube, 6 minutes, 24.05.2015).
• Accessible PDF screen reader demo (UC Systemwide Talent Management on YouTube, 2 minutes, 14.07.2020).
  This video shows how NVDA reads a correctly tagged PDF that contains headings, normal text, links and a data table.
• Blackmore, Gershon: The Importance of Role Mapping in Acrobat, Level Access blog, 27.04.2015.
• L’accessibilité PDF : une nécessité pour un web accessible, Ipedis (no date; accessed on 07.09.2022).
• Stephens, Mark: What is tagged PDF?, IDR Solutions blog, 19.05.2023.
• Questions and Answers about Tagged PDF, PDF Association (no date; accessed on 25.06.2024).
• Understanding Tagged (Structured) PDF, Adobe Blog, 16.01.2006.

Accessible Tables in PDF

• Creating Accessible Tables in PDF Files (Points of Access with Philip White on YouTube, 2019): this is a YouTube playlist containing videos on fixing PDF tables and fixing reading order.
• Frölich, Dirk: Barrierefreie Tabellen in PDF-Dokumenten – Teil I/III: PDF-Dokumente mit Word erstellen (df-edv on YouTube, 10 minutes, 21.03.2018).
  In this video, a Word document containing both a normal table and a complex table is converted to PDF using Word's built-in PDF export feature and evaluated using PAC 3.
• Frölich, Dirk: Barrierefreie Tabellen in PDF-Dokumenten - Teil II/III Fehlerkorrektur mit Adobe Acrobat (df-edv on YouTube, 15 minutes, 10.04.2018).
  This video continues where the previous one left off. It shows that PAC 2 does not find the accessibility issues inside the tables that PAC 3 detected. It shows how to add the scope attribute to table header cells (required by PDF/UA)
• Frölich, Dirk: Barrierefreie Tabellen in PDF-Dokumenten - Teil III - QuickFix (df-edv on YouTube, 11 minutes, 24.04.2018).
  This video shows to solve a number of accessibility issues in tables using axesPDF QuickFix. This tool uses some of the same libraries that have been integrated into PAC 3.
• Blackmore, Gershon: Tagging Complex Tables, Level Access Blog, 02.05.2017, updated on 31.01.2021.
• Brusnighan, Dean (Purdue University): Making Tables More Accessible (Adam Barragato on YouTube, 4 minutes, 18.11.2017).
  This video shows the Touch Up Reading Order tool, how to check the reading order, how to check whether table header cells are correctly marked up (and how to change this if this is not the case). In the video's last minute, Brusnighan briefly discusses complex tables and refers to Gershon Blackmore's article Tagging Complex Tables.
  (This video assumes that the PDF file is already tagged and not protected; if the file is protected, the Reading Order button in the Accessibility panel is disabled.)
• Fixing PDF Tables for 508 Compliance Manual Tagging (Points of Access with Phillip White on YouTube, 13 minutes, 31.05.2019).
  The process shown in this video begins with an untagged PDF document and first tags all the table cells, creating table row elements, moving the table cells into the rows, moving the row into a table element, changing the markup for table headers from TD to TH, checking the results in the Reading Order dialog, editing the table Table Editor Options, fixing the spanning of columns, fixing row heading spans, defining headings scope, setting IDs for column headings and row headings, and adding heading markup.
• Web Accessibility - PDF Table Prep with Screen Reader and Read Out Loud Demos (ODE HelpDesk on YouTube, 10 minutes, 01.12.2016).
  This video first shows how a screen reader reads a table in Microsoft Word if table headers have not been marked up and how the corresponding PDF version is read. It then shows how to fix the table in Adobe Acrobat 11 Professional: it uses the Touch Up Reading Order tool for to fix a few accessibility issues outside the table, then creates header cells in the table, assigns IDs to them and then connects the data cells with those header IDs. It then shows what the resulting table sounds like in a screen reader. It also show the Read Out Loud functionality in Adobe Acrobat, which is not a true screen reader and ignores the connections between the data cells and the header cells.
• PDF Accessibility Table Headers and Summary (Shawn Jordison on YouTube, 3 minutes, 25.12.2020).
• Castro, Dax: PDF Accessibility Merging Tables (PDF Accessibility on YouTube, 8 minutes, 17.02.2020).
  This video shows a table with a header row that is repeated at the top of each table; the table header row on the second and subsequent page are turned into artefacts. After deleting the redundant table header row elements, all table rows are moved into the same table body element.
  The sample PDF files used in this video can be downloaded from the page Merging tables that break across multiple pages (17.02.2020).
• Huber, Serge: After Flash, why PDF must die !, AIIM blog, 25.04.2012.
• Panchang, Sailesh: Inaccessibility of EN301-549 (PDF format) Standards for screen reader users, w3c-wai-ig@w3.org Mail Archives, 03.07.2022.
  This is the first message of a thread about this issue.

Accessible PDF Forms

• University of Washington: Creating Accessible PDF Forms Using Adobe Acrobat Pro (no date).
• Advanced PDF Accessibility with Adobe Acrobat Pro DC: Forms (UA Technology Accessibility on YouTube, 59 minutes, 01.05.2019).
• Advanced PDF Accessibility with Adobe Acrobat Pro DC: Forms (UA Technology Accessibility on YouTube, 56 minutes, 25.11.2019).

In the USA, Chapter 5 of Section 508 references PDF/UA directly:

504.2.2 PDF Export: Authoring tools capable of exporting PDF files that conform to ISO 32000-1:2008 (PDF 1.7) shall also be capable of exporting PDF files that conform to ANSI/AIIM/ISO 14289-1:2016 (PDF/UA-1) (incorporated by reference, see 702.3.1).

As of May 2022, Adobe Acrobat is not a very good tool to help achieve PDF/UA conformance. First, its plugin for Microsoft Office (Adobe PDF Maker) does not generate PDF/UA-conforming files out of accessbie source documents. Second, its built-in accessibility checker and its remediation features are too limited:

1. The checker does not verify whether a PDF file conforms to PDF/UA.
2. The checker cannot check whether the tag sequence is meaningful (see SC 1.3.2 in WCAG 2.1).
3. The checker cannot check whether the headings are meaningful (see SC 1.3.1 and 2.4.6 in WCAG 2.1).
4. The checker cannot check whether text alternatives are meaningful (only whether they are present) (see SC 1.1.1 in WCAG 2.1).
5. The checker cannot check whether text contrast is sufficient (see SC 1.4.1 in WCAG 2.1).
6. The checker cannot check whether non-text contrast is sufficient (see SC 1.4.11 in WCAG 2.1).
7. The checker cannot check whether table heading cells have a proper scope (see SC 1.3.1 in WCAG 2.1). (It does not warn authors when a table heading cell has its scope set to “none”. Fixing incorrect scope is complicated.)
8. The checker cannot check whether every item has an assigned tag. (PAC finds many issues of this type that Adobe Acrobat does not report.)
9. The checker cannot check whether labels for form elemens are meaningful (see SC 2.4.6 in WCAG 2.1).
10. The tool does not offer an easy way to add the PDF/UA identifier to a file.

Admittedly, a number of the above issues cannot be detected by any automatic tool. However, some word processors have checkers that check colour contrast.

Accessible PDF and InDesign

• Accede PDF Project: Accessibility of PDF (English translation of Accessibilité des documents PDF et ePub).
  Guidelines for making PDF documents accessibile with Adobe InDesign; you can even download a practice document.
• Les notices accessibilité InDesign et Acrobat, AcceDe PDF, 05.08.2022.
• Posselt, Klaas: Optimale PDF-Dokumente für das Web mit InDesign erstellen – diese Features machen Leser glücklich(er), Creative Aktuell, 05.03.2021.
• Wie Sie PDF-Formulare aus InDesign richtig auf die Barrierefreiheit überprüfen, Creative Aktuell (no date; accessed on 14.07.2021).
• Hugo, Matthias: Tutorial wie Sie in 12 Schritten mit Adobe InDesign barrierefreie PDFs erstellen, Konturenreich, 26.03.2019 (updated on 10.05.2021).
• PDF depuis InDesign, AnySurfer, last updated on 19.08.2020.
• PDF vanuit InDesign, AnySurfer, last updated on 19.08.2020.

Checking PDF Accessibility

• PAC 2021 - The Free PDF Accessibility Checker, PDF/UA Foundation (no date; accessed on 10.08.2021).
  This accessibility checker was released in August 2021 as the successor of PAC 3. German page: PAC 2021 - Der kostenlose PDF Accessibility Checker.
• Your PDF Accessibility Checker – axesCheck: online PDF accessibility checker. (Accessed on 30.01.2024.)
• PDF Accessibility Checker (PAC) 2021, axesPDF Support-Plattform, updated on 13.09.2021.
• How to check if a PDF is accessible using PAC 3 0 (Accessibility on YouTube (University of Akron University Libraries), 2 minutes, 25.06.2020).
• Testing PDFs for Accessibility and Standards Conformance, CommonLook, 26.08.2020.
• PAVE: Validate and Fix PDF Accessibility: this site has an online PDF accessibility checker. The YouTube video “Introduction to PAVE v2.0” shows how the tool works. There is also a German version of the video.
• veraPDF: Industry Supported PDF/A Validation (accessed on 13.08.2021). Licensing: veraPDF is dual-licensed under the GNU General Public License v3 or later (GPLv3+) and Mozilla Public License v2 or later (MPLv2+).
  Pull request #1068: PDF/UA validation, merged in March 2020, seems to suggest that this tool also validates PDF/UA (or the presence of the PDF/UA identifier). See also veraPDF 1.18 includes support for PDF/UA-1 (PDF Association, 22.04.2021). PDFUA Part 1 rules (inveraPDF's GitHub wiki) specifies the checks for PDF/UA supported by veraPDF. (Accessed on 18.05.2022.)
  Unlike PAC 2021 and its predecessor PAC 3, veraPDF checks can be run from the command line, which allows automation. See veraPDF CLI Validation. See also veraPDF-apps: Command line and GUI industry supported PDF/A and PDF/UA Validation (accessed on 29.12.2023).
  See also Boris Dubrov's presentation Open source implementation of PDF/UA validation (PDF Association on YouTube, 29 minutes, 24.11.2020; recorded at the OctoberPDFest in 2020). veraPDF was developed during the Preforma project, which started in January 2014 and received funding from the European Union.
• Stiftung «Zugang für alle»: PDF Accessibility Checker (PAC 3). This is a PDF accessibility checker for Microsoft Windows (all versions since Windows Vista). It is a freeware product, but users are not allowed to distribute copies of the software or to automate the accessibility evaluation process. (Released in December 2017.)
• Stiftung «Zugang für alle»: PDF Accessibility Checker (PAC 3).
• Check the Accessibility of a PDF Document, Tingtun Checker (no date; accessed on 10.08.2021).
  A note below the submission form says, The service is still being developed. If you discover a bug, have questions, or suggestions for improvement, please give us your feedback. This is presumably the checker developed by Anand B Pillai (see below) and originally hosted at www.egovmon.no.
  See also the short PDF accessibility FAQ and the list of Checker PDF Tests.
• Anand B Pillai: PDF Accessibility with Python, PyCon India 2010, 2010.
  Summary: The talk will be focused on a project that Anand developed along with the "Egovmon" (E-government monitoring, www.egovmon.no) project based in Norway for measuring the accessibility of PDF documents used by municipalities across Norway. The project is sponsored by a set of 20 municipalities in Norway and Difi, (The Agency for Public Management and eGovernment) Norway and consists of an online interactive PDF checker which allows the user to submit a PDF URL and obtain accessibility metrics immediately.

Other PDF Tools

• axesPDF für Word: this is a commercial extension for Microsoft Word (version 2013 or higher) for Windows (Windows 7 or higher with .NET Framework 4.6.2).
• iText PDF: a PDF generation library for Java and .NET. It supports PDF XA and can convert PDF to HTML.
• Chapter 7: Creating PDF/UA and PDF/A documents, iText, 22.04.2020 (accessed on 16.07.2021).
• The PDF/UA-1 Standard for Universal Accessibility, PDFLib (no date; accessed on 15.07.2021).
  In addition to general information about the standard, this article also links to examples of PDFlib 9 application code.
• Convert HTML to PDF, Prince XML (no date; accessed on 07.10.2021). See also Prince Output, which says that Prince supports tagged PDF and PDF/UA-1.
• PrinceXML, npm, 2018.
• ravdocs: Node API for executing PrinceXML via prince(1) CLI, ravdocs on GitHub.
• Lawson, Bruce: Making accessible tagged PDFs with Prince, Bruce Lawson, 15.07.2019.
  Bruce Lawson had been doing some work for YesLogic, the vendor of Prince XML.
• Moore, Ross: Authoring accessible ‘Tagged PDF’ documents using LATEX, Macquarie University, September 2018.
• 'tagged-pdf' tag wiki, TeX - LaTeX Stack Exchange.
• Making LaTeX produce tagged and accessible PDF, PDF Association, 27.01.2021.
• DocRaptor: HTML to PDF API (powered by the Prince HTML-to-PDF engine) (accessed on 28.07.2021).
• PDF/UA – with focus on accessibility, FineReader Blog, 09.01.2019.
  This blog post explains what PDF/UA is and how you can create PDF/UA documents with FineReader. (The process relies on OCR and it is not obvious how OCR alone can be used to generate an accessible PDF document.)
• PDF-Lib (no date; accessed on 20.07.2020).
• Apache PDFBox®, Apache Software Foundation (no date; accessed on 10.08.2021).
  The developers describe the library as follows: The Apache PDFBox® library is an open source Java tool for working with PDF documents. This project allows creation of new PDF documents, manipulation of existing documents and the ability to extract content from documents. Apache PDFBox also includes several command-line utilities. Apache PDFBox is published under the Apache License v2.0.
• Das, Ankush: Best PDF Editors for Linux to Edit the PDF Content and Extract Pages to Merge in Other PDF Files, It's FOSS, 29.10.2020.
  Some of the tools or editors listed in the articles are not open source. The open-source tools are LibreOffice Draw, Okular (a viewer rather than an editor), Scribus (a desktop publishing tool), PDF Mix Tool, PDFsam, PDFArranger, PDF Chain and PDF Slicer.
• VIP-PDF-Reader, Zugang für alle (no date; accessed on 08.10.2021).
• simplA11yPDFCrawler, AccessibilityLU (Luxembourg) on GitHub (accessed on 23.02.2023).
  Description: This tool crawls a list of websites and download all PDF and office documents. Then it analyses the PDF documents and tries to detect accessibility issues. This tool is available under the terms of the MIT licence.

PDF Accessibility Standards and Background Documents

• ISO 14289-1:2014 - Document management applications — Electronic document file format enhancement for accessibility — Part 1: Use of ISO 32000-1 (PDF/UA-1), ISO, 2012 (accessed on 15.07.2021).
  The first version of this standard was published in 2012. The revised version from 2014 was last reviewed and confirmed in 2020. Note that many subchapters in this document reference ISO 32000-1:2008: Document management — Portable document format — Part 1: PDF 1.7, which was last reviewed and confirmed in 2018. ISO 14289-1 is of limited use without access to ISO 32000-1.
  This is not a “publicly available standard”; readers must purchase it from ISO or from one of its national member organisations.
  (ISO 32000-1 is not to be confused with ISO 32000-2:2017, which was withdrawn and replaced by ISO 32000-2:2020: Document management — Portable document format — Part 2: PDF 2.0 in 2020. )
• Drümmer, Olaf; Chang, Bettina: PDF/UA in a Nutshell (PDF), PDF Assocation, 01.08.2013.
  PDF/UA is defined by ISO standard 14289-1, which was first published in 2012. The document is partially outdated because WCAG 2.1 has succeeded WCAG 2.0, the European Commission's Mandate 376 has led to the creation of the European standard ETSI EN 301 549 and the European Accessibility Act (Directive (EU) 2019/882)) was published in April 2019.
  German version: PDF/UA kompakt. Barrierefreie Dokumente mit PDF.
• Erle, Markus: PDF/UA Basics — Markus Erle, wertewerk (PDF Association, 22.06.2014. This is a video recording of a presentation at the PDF Days Europe 2014 (June 2014).
• Rayius, Paul: WCAG 2.1 and PDF Accessibility, Common Look, 25.06.2019.
  Discusses some of the success criteria that were added in WCAG 2.1 and their relevance to PDF. Some of these new criteria are typically not relevant to PDF: 2.2.6 (Timeouts) and 2.5.2 (Pointer Cancellation).
• WCAG 2.0 Mapping to PDF/UA, Adobe, 24.11.2019 (accessed on 05.08.2021).
• Accessible PDF: A Glossary of Terms, CommonLook, 31.05.2019.

PDF Accessibility on macOS

Support for tagged PDF on macOS has long been poor:

• Johnson, Duff: Inaccessible by Choice: PDF on MacOS, Duff Johnson Strategy & Communications, 01.03.2013.
  The opening paragraph states the basic issue: An accessibility expert pointed out the other day that VoiceOver, Apple’s screen reader for MacOS, doesn’t understand tagged PDF, and therefore doesn’t support accessibility in this extremely common electronic document format. The free and open-source screenreader NVD, by contrast, does support tagged PDF, but works only on Microsoft Windows.
• Kiss, Jason: MS Word not an accessible alternative, NZ Digital government blog, 24.07.2014.
  Quotes:

  Historically, there has been very limited accessibility support for PDF and MS Word on Mac OS and Linux, although those platforms represented a small proportion of desktop user technologies. However, those limitations have only expanded with the rapid uptake of mobile technologies and popular iOS and Android platforms, which also poorly support PDF and Word. Accordingly, neither PDF nor Word can currently be considered accessibility supported technologies for the purpose of conformance with the NZ Government Web Accessibility Standard.

  Unfortunately, both PDF and Word documents have very limited accessibility support on the Mac OS and Linux platforms for screen reader users. For instance, in Mac OS, the VoiceOver screen reader does not communicate to users the semantic structure (e.g. what's a heading, what's a table column header, etc.) that otherwise accessible Word or tagged PDF documents contain. Similar screen reader support issues with PDF and Word documents exist on mobile platforms, iOS and Android.

• How do I make VoiceOver read paragraphs in InDesign-created PDF without pausing on each line? This question was posted on Stack Overflow on 18 June 2019 and had not yet received any answers by mid October 2019.
• Vision Accessibility – Mac, Apple, no date; accessed 16.10.2019.
  Quote: We’ve refined VoiceOver to make it easier to navigate PDFs, websites, and messages. In Safari, improved conformance with HTML5 accessibility standards allows for more consistent navigation of websites. VoiceOver is now better at reading aloud tagged PDFs and email messages.
• Johnson, Duff: Apple tags PDF, PDF Association, 13.11.2019.

Older Resources about Accessible PDF

• Reid, Loretta Guarino; Haritos-Shea, Katie; Chisholm, Wendy: PDF Techniques for Web Content Accessibility Guidelines 13 September (Internal Working Draft 13 September 2001), World Wide Web Consortium, 2001. (This document is out of date and of historical interest only.)
• Anand B Pillai: PDF Accessibility with Python, PyCon India, Bangalore, September 2010. The conference presentation reports on PDF accessibility checking code developed within the eGovMon project in Norway.
• Comme tout fichier numérique appelé à être diffusé publiquement, un PDF parfait doit être balisé et accessible, abracadabraPDF, 20.06.2014, updated on 07.07.2017.

Other Resources about PDF

The following resources are listed here temporarily. They are not related to accessibility; some research is required on their impact on accessibility or on how certain features and capabilities described in them can be used in an accessible manner.

• Harder, Jennifer: Enhancing Adobe Acrobat DC Forms with JavaScript. Apress, 2017. (XXIV + 363 pages) ISBN 978-1-4842-2893-7 (e-book) / 978-1-4842-2892-0 (softcover).
• Applying actions and scripts to PDFs, Adobe (no date; accessed on 20.07.2020).
• PDF/X-, PDF/A-, and PDF/E-compliant files (Acrobat Pro), Adobe (no date; accessed on 05.11.2021).
• Hagelberger, Kathleen: How to Use Adobe Acrobat Pro DC to Make Interactive PDFs For Inbound Marketing, Cypress North, 02.10.2020.
  (This article contains a worked example that uses Acrobat JavaScript.)
• Subhash, V.: An Acrobat Javascript primer with simple PDF examples, Gnostice, June 2015.
• Acrobat Javascript Samples Scripts, evermap (no date; accessed on 20.07.2020).
• Parker, Thom: How to do (not so simple) form calculations, Acrobat Library (AcrobatUsers.com), 02.07.2006.
• Parker, Thom: The Acrobat JavaScript Console (Your best friend for developing Acrobat JavaScript), Acrobat Library (AcrobatUsers.com), 28.10.2013.
• How to enhance your PDF forms with JavaScript, Scribus Wiki (no date; accessed on 20.07.2020).
• JavaScript APIs and Forms, Acrobat Mobile Deployments (no date; accessed on 20.07.2020).
  Note that these APIs are a subset of those supported on the desktop.
• pdfscripting.com (no date; accessed on 20.07.2020).
• JavaScript PDF form filling library, PDFTron SDK (no date; accessed on 20.07.2020).
• Tester l'accessibilité d'un document PDF, AnySurfer, last updated on 23.01.2020.

Audio and Video

Captioning Guidelines

• BBC: How do I create subtitles?, Academy Guides (BBC), no date (presumably 2019). (Last accessed on 21.08.2024.)
• BBC: Subtitle Guidelines, BBC, version 1.2.3, June 2024 (accessed on 21.08.2024).
• Deleted: BBC: BBC Subtitle Guidelines (version 1.1.9, September 2021; accessed on 16.11.2021). These guidelines are no longer available on GitHub pages; the link redirects to the BBD website.
• Captioning Key: Guidelines and Best Practices for Captioning Educational Video. (Last accessed on 21.08.2024.)
• Untertitel-Standards, Das Erste (first published in April 2015).
• Untertitel-Standards von ARD, ORF, SRF, ZDF, Das Erste (updated in April 2020).
• Untertitel-Standards von ARD, ORF, SRF, ZDF, ZDFmediathek, 10.04.2015 (accessed on 21.08.2024).
• Gemeinsame Untertitelrichtlinien für den deutschen Sprachraum: guidelines defined by several associations that represent people with hearing impairments. These guidelines cover aspects such as line length, timing and transcribing non-speech sounds
• Vasseur, Cédric: Sous-titrer une vidéo, handisol.beepmaster.com, 27.09.2010, updated several times. This document covers both technical steps and, to a lesser extent, subtitle formatting and content.
• knarf18 / Frank Galey: Liste bonnes pratiques sous-titrage web, GitHub Gist, last updated in 2015 (accessed on 23.02.2023).
• Zarate, Soledad: Captioning and Subtitling for d/Deaf and Hard of Hearing Audiences, ResearchGate, January 2021.
• Doet de taal van de ondertiteling van een video er toe?, WCAG Audit Discussies in Nederland en Vlaanderen, January 2022.
  This issue gives the (real or imaginary) example of a website in Dutch that contains a video in Dutch with captions in English and asks whether this fails WCAG and, if yes, which success criterion. (The question would have been more complex if the video had been in English with Dutch captions.)

Tools for Captioning / Subtitling

Note that the USA and the UK use different terms: the American English term “captions” corresponds with the British English term “subtitles” or more accurately “subtitles for the deaf and hard of hearing”. As a rule, the tools listed below can be used both to create regular subtitles (which translate spoken content) and subtitles for the deaf and hard of hearing (which transcribe spoken content and non-speech sounds, possibly with additional features).

YouTube can automatically generate captions for a number of languages, but these need a lot of work afterwards. Proper names are often misunderstood. For example, in the video Review: Three Essential Historical Recordings, the title of the opera Pelléas et Mélisande is misinterpreted as “Paleo Sommeliers”.

• Olsson, Nikolaj Lynge (nikse.dk): Subtitle Edit: free and open source editor for video subtitles. Requires the .NET framework 4.7.2 (or newer).
• Amara: web-based tool supports captioning in YouTube and Vimeo Created by a non-profit project.
• WGBH: CADET: Caption And Description Editing Tool. According to the description on the website (status on 13.09.2019), CADET is free, downloadable caption-authoring software that enables anyone to produce high-quality caption files that are compatible with any media player that supports the display of captions. CADET can also be used to generate audio-description scripts.
  CADET requires Node.js and runs on Windows, macOS and Linux.
• Jubler Subtitle Εditor: free and open-source tool (GPL 2 licence) written in Java. The code in Jubler's GitHub repository was last updated in June 2020 (except for the pom.xml file, which was updated in June 2022). (Last accessed on 15.03.2023.)
• STAMP: Subtitling Add-In for PowerPoint (free and open source). The code in the SourceForge repository has not been updated since 2018. The add-in may not be compatible with Microsoft Office version more recent than version 2016. (Last accessed on 15.03.2023.)
• Subtitle Workshop: free and open-source tool (GPL 3 licence), apparently only for Windows. The code in the SourceForge repository has not been updated since 2013. (Last accessed on 15.03.2023.)
• gaupol: free and open source tool (GPL 3 licence) for Linux. The tool is available as a package in several Linux distributions, as a Flatpak and as source code. Windows versions are no longer available. This tool is still being actively developed. (Last accessed on 15.03.2023.)
• GNOME Subtitles: free and open source tool for GNU/Linux. This tool is maintained by the GNOME project; see GNOME Subtitles in GNOME's GitLab repository. (Last accessed on 15.03.2023.)
• Subtitle Composer: free and open source tool developed by the KDE project. It is available for Microsoft Windows and most major Linux distributions. It does not support the VTT format. (Last accessed on 15.03.2023.)
• Subtitle Editor: free and open source tool for Linux and BSD operating systems. It does not support the VTT format. The source code in kitone's GitHub repository was last updated in 2019, except for changes in the readme document.. (Last accessed on 15.03.2023.)
• noOp's subtitle is an open source tool written in Java that can be used to convert subtitles (and captions) from one format to another. The supported formats include VTT, SRT and sami. This tool is still maintained. (Licence: LGPL.) (Last accessed on 15.03.2023.)
• subedit: a command line subtitle editor for the Bash shell (Linux and probably also the BSD family). It works mainly with the SubRip (srt) format. The code in the subedit repository was last updated in November 2020. (Last accessed on 15.03.2023.)
• dotSUB: VideoTMS platform (commercial). (Last accessed on 15.03.2023.)
• Subtitle Editor, MFD Subtitle Edit (no date; accessed on 29.06.2022).
• Subtitle Converter, GoTranscript (no date; accessed on 23.06.2022).
  This online tool can convert to 15 formats, including SubRip (srt), TimedText 1.0, WebVTT (vtt), SAMI and SBV. (Last accessed on 15.03.2023.)
• Jean-Marc: Les 16 meilleurs logiciels de sous-titrage : le guide ultime, Checksub, 19.02.2021. (Last accessed on 15.03.2023.)
• AHD Subtitles Maker Professional: free and open source tool (GPL 3 licence). The source code is no longer available on SourceForge.
  AHD Subtitles Maker: free and open source tool (GPL 3 licence) for Microsoft Windows only.
• CaptionTube.

The above list does not cover tools for adding captions or subtitles using respeaking and voice recognition.

Google Chrome added support for live captioning in March 2021:

• Campbell, Ian Carlos: Chrome now instantly captions audio and video on the web, The Verge, 17.03.2021.
• Low, C.: Chrome can now caption all audio playing through the browser, Engadget, 18.03.2021.
• Arici, Alexandra: How to Enable Live Captions for Videos in Chrome for Desktop, Make Tech Easier, 16.04.2021.

Possibly usable for transcribing audio:

• Otter ai (commercial product).
• Fireflies.ai (commercial product).
• OpenAI Whisper: a general-purpose speech recognition model. Written in Python. Open source; licence: MIT.

Tutorials on Captioning

• University of Washington: Creating Accessible Videos.
  This document discusses captions, audio description, live captioning, live description, transcripts and choosing an accessible media player (the recommended player is Able Player).
• Rubin, Jonathan; Leisinger, Ryan; Morin, Gary: 508 Accessible Videos – How to Make Audio Descriptions, Digital.gov.
• Lewis, Whitney: A complete guide for adding captions to YouTube videos, Pope Tech Blog, updated on 03.06.2024.
• Quick Captioning with YouTube (Carmen Wiki, Office of Distance Education and eLearning, Ohio State University). (The CarmenWiki was decommissioned on 31.01.2019.)
• Knott, Ryan: How to Add Captions or Subtitles to a Video, TechSmith blog, 2017, updated later (accessed on 30.11.2021).
  German version: Untertitel in Videos einfügen – So geht es!.
• How to Add Subtitles and Captions to Camtasia, Rev, 10.03.2020.
• How to Add Subtitles, Corel Discovery Center (no date; accessed on 30.11.2021).
  How to add subtitles in VideoStudio: either manually or automatically.
• Adding titles with the Subtitle Editor, Corel VideoStudio Pro Help (no date; accessed on 30.11.2021).
• How To Add Subtitles To Video in VideoStudio, VideoStudio Pro (Corel) (no date; accessed on 30.11.2021).
• DIY Captioning Techniques (Carmen Wiki, Office of Distance Education and eLearning, Ohio State University). (The CarmenWiki was decommissioned on 31.01.2019.)
• 3PlayMedia: Captions and Subtitles in PowerPoint: tutorial for adding captions or subtitles to videos in PowerPoint 2013 or Office 365 using Office Mix.
• TechSmith: Add Captions Manually - Camtasia Version 8. (See also this video tutorial on YouTube.)
• How to Add ASR (Automatic Speech Recognition) Captions into a Video, Panopto, 08.11.2021.
• How to Upload a Caption File for a Video, Panopto, 11.02.2021.
  Panopto supports the following upload formats: SRT, ASHX, VTT and DXFP.
• Frequently Asked Questions (FAQs) About Video Captioning, Answered, Panopto (no date; accessed on 30.11.2021).
• Young, Mako: How to Add Subtitles (or Captions) to a Video, VEED.IO (no date; accessed on 30.11.2021).
• Automatically Translate and Subtitle Videos with a Few Clicks - VEED.IO (VEED STUDIO on YouTube, 4 minutes, 28.08.2020).
  Shows how you can automatically generated subtitles in the language of the video and then have these subtitles automatically translated. You can download the subtitles in various formats, including SRT and VTT.
• Thompson, Terrill: Handling Captions via the YouTube Player API, Terrill Thompson, 13.04.2015.
• Adding captions and subtitles to HTML5 video, MDN Web Docs, no date.
• Create closed captions for a video, Microsoft Office Support, no date (accessed 05.12.2019).
  This article applies to PowerPoint for Office 365 and PowerPoint for Office 365 for Mac.
• Record a slide show with narration and slide timings, Microsoft Office Support, no date (accessed 05.12.2019).
  This article applies to PowerPoint for Office 365 and PowerPoint for Office 365 for Mac.
• Microsoft Stream automatically creates closed captions for videos, Microsoft Office Support, no date (accessed 05.12.2019).
  This article applies to PowerPoint for Office 365 and PowerPoint for Office 365 for Mac.

Quality and Accuracy of Captions

• Closed Captioning of Video Programming: Report and Order, Declaratory Ruling, and Futher Notice of Proposed Rulemaking (PDF), Federal Communications Commission (FCC), 24.02.2014. (Referenced from Closed Captioning Quality Report and Order, Declaratory Ruling, FNPRM.) Pages 20–21 contain the following statement about captioning accuracy (with footnote references removed): In order to be accurate, captions must match the spoken words in the dialogue, in their original language (English or Spanish), to the fullest extent possible and include full lyrics when provided on the audio track. Specifically, to accurately convey the dialogue in a program, closed captions need to contain all words in the order spoken, without paraphrasing or substituting words for proper names and places, contain proper spelling (including appropriate homophones, such as “their,” not “there”), and provide, as needed to understand the program, appropriate punctuation and capitalization to reflect natural linguistic breaks and the flow of the dialogue, the proper tense, and the accurate representation of numbers (including currency figures with appropriate symbols or words). Accurate captions do not rewrite dialogue, or use synonyms to replace actual dialogue because this fails to capture the program’s content and nuances. To this end, where necessary to understand a program’s content, accurate captions also convey the manner and tone of the speaker’s voice. Similarly, where slang or grammatical errors are intentionally used in a program’s dialogue, accuracy dictates that captions mirror such slang and errors, so that viewers can fully understand the speaker’s intent and message. Although we recognize that utterances (e.g., “um”) and false starts may not be as critical to a program’s content, accuracy also requires that these be captioned if needed for the viewer to understand the program.
  Another statement concerns non-speech sounds: In order to be accurate, captions must also provide nonverbal information that is not observable, such as who is speaking, the existence of music (even when there are no lyrics to be captioned), sound effects, and audience reaction, to the greatest extent possible, given the nature of the program. If there is more than one speaker, the proper placement of captions dictates that each speaker be identified, through caption identification or caption placement, so that viewers can understand who is speaking at any given time. When a speaker is not on the screen, identification of that individual in the caption text must also be provided if viewers not using captions are able, from the program’s audio content, to discern the speaker’s identity. Finally, in order to be considered accurate, captions must also be legible, with appropriate spacing between words to allow for readability.
• Lewis, Elisa: What Is 99% Accuracy, Really? Why Caption Quality Matters, 3Play Media blog, 07.06.2021.
  Quote: The industry standard for captioning accuracy is 99%.
  A 99% accuracy rate means that there is a 1% chance of error or leniency of 15 errors total per 1,500 words.
  Accuracy measures punctuation, spelling, and grammar. 3Play Media provides captioning services, so the blog post also gives a list of transcript errors that their competitors made. In the USA, inaccurate captions can have legal consequences. Quote: Both Harvard and MIT were sued for providing inaccurate captions on public facing videos.
  The outcome?
  The Department of Justice submitted a statement of interest agreeing that MIT and Harvard’s inaccurate captions fail to provide equal access to the deaf and hard of hearing.
• Lewis, Elisa: Captioning Accuracy: How to Measure Error Rates, 3Play Media blog, 11.04.2019, updated on 22.04.2021.
• Kincaid, Jason: Challenges in Measuring Automatic Transcription Accuracy, Descript (on Medium), 20.08.2018 (seven-minute read).
• Byrne-Haber, Sheri; Are bad captions better than no captions?, Sheri Byrne-Haber, CPACC on Medium, 29.03.2021 (seven-minute read).
  Google Chrome now has a feature for live captioning. The blog post lists several issues with automatically generated captions: incorrectly recognised words, a lack of attribution when there are multiple speakers in a video, bad punctuation, bad synchronisation and missing non-verbal sounds. 90% word accuracy is not very impressive is some of the other issues are present. Examples of low accuracy abound. For example, in a speech by Mitt Romney, the words “American Strength” were captioned as “airstrikes”. Caption accuracy can be affected by accents, acronyms, technical terms, non-English terms or names in the audio stream. Captioning is not a lot of work nowadays, so it should be done all the time.
  See also Meryl Evans's tweet showing three autocraptioned clips versus one that was captioned by hand (09.02.2021).
• Awad, Nick: Why 99% Accuracy in Captions Matters, Accessibility.com blog, 28.05.2024.
  Quote: When producing captions, one should aim for at least a 99% accuracy rate, meaning nearly all words transcribed accurately reflect the original audio. This standard recognizes the challenges in achieving absolute perfection due to speech complexities like diverse accents, rapid dialogue, and technical jargon.
• Closed Captioning Quality, National Association of the Deaf (NAD, USA (no date; presumably early 2015; accessed on 21.08.2024).
• If auto-captions are available on a video, does it need to be re-captioned to quality standards?, National Deaf Center on Postsecondary Outcomes (The University of Texas at Austin), last updated on 28.07.2022.
  This FAQ question quotes and references the FCC guide Closed Captioning on Television (last updated on 27.01.2021). One of the requirements in this guide is Accurate: Captions must match the spoken words in the dialogue and convey background noises and other sounds to the fullest extent possible. The accuracy level is not expressed as a percentage.
• NoMoreCraptions (open-source project that provides an alternative to YouTube's automatic captions, which are dubbed “craptions”).
• Berube, Chris: Craptions, episode 535, 99% Invisible, 01.05.2023 (recording of a podcast and its transcript).
• Ellis, Emma Grey: The Problem With YouTube's Terrible Closed ‘Craptions’, WIRED, 01.10.2019 (paywalled article).
  Subtitle: In the absence of manually transcribed captions, YouTube’s algorithm supplies auto-generated ones. The nonsensical results hurt everyone.
• Romero-Fresco, Pablo; Fresno, Nazaret: The accuracy of automatic and human live captions in English, Linguistica Antverpiensia, New Series – Themes in Translation Studies, volume 22 (2023; Creative Commons).
• Middleton, Wendy: Study calls for better film captions for the deaf, BBC, 12.05.2024.
  See also Rethinking Subtitles for Deaf Audiences on the website of the University of Sheffield (09.05.2024) and How do Deaf British Sign Language users experience suspense in film?, which also contains six recommendations to filmmakers.
• Romero-Fresco, Pablo; Martínez Pérez, Juan: Accuracy Rate in Live Subtitling: The NER Model, in Audiovisual Translation in a Global Context: Mapping an Ever-changing Landscape, edited by Rocío Baños Piñero and Jorge Díaz Cintas (Palgrave Macmillan, 2015).
• The Best Accuracy Measurement for Captions Yet: The NER Model, AI-media, 25.04.2023, updated on 28.09.2023. This is about live captioning.

Articles on Captioning

• Friedman, Vitaly: Designing for Accessibility: Best Practices for Closed Captioning and Subtitles UX, Smashing Magazine, 11.01.2023 (14-minute read)
• Greger, Sebastian: The UX design case of closed captions for everyone, Sebastian Greger, 07.02.2019 (accessed on 11.11.2023).
• Oregon State University: Ecampus Research Unit: National Research Study: Student Uses and Perceptions of Closed Captions & Transcripts.
• Robson, Gary: Does closed captioning still serve deaf people?, TEDxBozeman, May 2014 (10 minutes, YouTube).
• Thompson, Terrill: Free Tools for Captioning YouTube Videos, 02.08.2009.
• Morales, Jonathan: Video captions improve comprehension, professor finds, SF State News (San Francisco State University), October 2013.
• Kushalnagar, Raja S.: Optimizing Video Presentations for Deaf and Hard of Hearing Participants in Mainstream Classrooms, SIGACCESS blog, 01.12.2010.
• Die Vorproduktion von Untertiteln, Das Erste (no date; accessed on 03.05.2021).
• Untertitel – ARD, Das Erste, last updated on 09.04.2019 (accessed on 21.05.2021).
• Die Live-Untertitelung, Das Erste (no date; accessed on 21.10.2021).
• Warum sind Untertitel eigentlich ...?, NDR.de (no date; accessed on 21.10.2021).
  One of the questions discussed on this page is why subtitles don't scroll: Der NDR strahlt seine Untertitel in übersichtlichen Blöcken aus, weil der Text schnell erfassbar sein soll. Auf das Scrolling wird verzichtet. Diese Technik bindet den Blick des Zuschauers stärker als die Block-Methode. Außerdem kommt es beim Abschicken der Untertitel beim Scrolling häufig zu "Staus". Sender, die das Verfahren getestet haben, haben festgestellt, dass mehr Untertitel gesendet werden können, wenn diese in Blöcken veröffentlicht werden.
• Lewanczik, Niklas: 7 Gründe, warum Untertitel bei Videos ein Muss sind, OnlineMarketing.de, 18.07.2018.
  This marketing article discusses several reasons why captions are a must; accessibility is only one of these reasons.
• Clark, Joe: Captioning (links to Joe Clark's writing about captioning; not updated since 2007).
• Edelberg, Elisa: Next Stop, Section 508: Navigating Video Accessibility Laws, Association for Talent Development, 28.04.2020.
• Sous-titrez vos vidéos !, Ministère de l’Europe et des Affaires étrangères,, 10.01.2020 (last update).
• Le sous-titrage pour sourds et malentendants, Ciné-sens, 04.04.2014, updated on 22.09.2015.
• Dal Molin, Rémy; Jalis, Emma: Le time delay, kesako ?, blog Koena, 24.03.2022.
  French blog post about the slight delay in captions for live video.
• Boyrie, Mylène: Ce que j’ai appris en travaillant sur l’accessibilité de mes vidéos pour le Web, Mylène Boyrie, 27.06.2021.
• Wie entstehen Untertitel im ORF? (mabacherTV on YouTube, 17 minutes, 14.08.2016).
  This video covers a number of challenges involved in subtitle television programs. For example, news programs are sometimes updated with new sections a few minutes before the start of the program. Subtitling live broadcasts relies on respeaking, which also has its challenges, such as homophones (e.g. Lehre versus Leere, or Punkt as a noun versus Punkt to insert a full stop). The interviewee also explains when and how different colours for subtitles are used. When subtitling live interviews, some information may get shortened or partially skipped.
• Leduc, Jaclyn: Overview of NAD v. Harvard and NAD v. MIT Lawsuits, 3Play Media blog, 25.03.2020.
• Untertitel sind kein Luxus, Stufenlos, 22.01.2017.
• Fisseler, Björn: Barrierefreie Audio- und Videoinhalte erstellen, Hochschulforum Digitalisierung, 16.10.2020.
• The Majority of Young People Are Using Subtitles When They Watch TV, YPulse, 22.11.2022.
• Mykhalevych, Nadiia: Survey: Why America is obsessed with subtitles, Preply blog, 13.10.2023 (seven-minute read).
  Quote: Recent data has shown that younger generations overwhelmingly prefer to watch content with subtitles on. (This refers to data published by the BBC.) Preply suveyed 1,200 Americans and found, among other things, that 50% of Americans watch content with subtitles most of the time and that 55% say it is harder to hear dialogue in shows and movies than it used to be.
• Wilhelm, Daley: Subtitles are standard: mainstreaming accessibility, UX Design on Medium, 12.08.2023 (seven-minute read; member-only content).
  Quote: Do you watch movies with subtitles on? In a Preply survey of 1,260 Americans, 50% said that they use subtitles most of the time. This goes for more than just movies: most social media feeds that feature videos have features that allow for automated or manual subtitles. It makes sense then when further studies have found that the overwhelming majority of younger generations use subtitles almost constantly.
• Mary Ellen Dello Stritto; Katie Linder: A Rising Tide: How Closed Captions Can Benefit All Students, Educause, 28.08.2017 (Creative Commons BY-NC-ND 4.0).
  From the key takeaways: Regardless of whether they have a disability of any kind, a majority of students use closed captions at least some of the time. Specific ways in which closed captions can aid learning include comprehension, accuracy, engagement, and retention.
• Cunningham, Katie: Mumbling actors, bad speakers or lazy listeners? Why everyone is watching TV with subtitles on, The Guardian, 27.01.2023.
  Subtitle: Subtitles aren’t just for the hard of hearing, with Netflix reporting 40% of its viewers regularly use them. But do we just enjoy them or is there a more annoying reason?
  Quote from the article: Last year, Netflix revealed that 40% of its global users have subtitles (more commonly known as “closed captions” in some countries) on all the time, while 80% switch them on at least once a month – stats that far exceed the number of viewers who need captioning because of hearing impairment.
  There are, of course, a myriad of reasons why someone might turn on the subtitles: a sleeping baby in the other room they don’t want to wake, a noisy flight path above, or an unintelligibly thick accent from an international actor (something that is becoming more common as streaming brings television from around the globe into our homes).
• Youngs, Ian: Young viewers prefer TV subtitles, research suggests, BBC News, 15.11.2021.
• Was sind Untertitel für Gehörlose, Intertitula (no date; accessed on 28.10.2021).
• Untertitel vs. Captions: Was ist der Unterschied?, Ambersript blog, 26.02.2020, last updated 18.10.2021..
  Even though the article is in German, it discusses subtitles for the deaf and hard of hearing (SDH) and closed captions.
• Higgs, Chris: Subtitles for the deaf and the hard of hearing on TV. Legislation and practice in the UK, inTRAlinea. online translation journal, Special Issue: Respeaking, 2006 (Creative Commons).
• Untertitelung für Gehörlose und Hörgeschädigte (SDH), Untertitelforum – AVÜ e.V. (no date; accessed on 28.10.2021).
  This page discusses SDH, as opposed what this website calls OmU-Untertitelung. See also the related page Untertitelung "Original mit Untertiteln".
• DGB fordert offene Untertitel in Kinos, Deutsche Gehörlosenzeitung, 03.04.2019.
• How to Create Videos for Different Social Media Platforms, Learn to Flourish, 11.11.2019.
  This article is interesting mainly because of the following statement: A large number of viewers on Facebook watch videos without audio. Adding subtitles to your video will allow people to enjoy the entire message of your video without turning on the volume.
• Jackson, Izak: This is Why Every Video Needs Subtitles, Votla-Media blog, 23.04.2021.
  Quotes: 85% of Facebook videos are now watched on mute which is a common trend seen across all social media platforms. Not only are people choosing to watch videos without audio, but the majority of social media platforms will autoplay videos with the audio turned off. Research also found that videos that included subtitles on Facebook had 16% higher reach than those without. They also had 15% more shares, 17% more reactions, and 26% more call-to-action click-throughs.
• Patel, Sahil: 85 percent of Facebook video is watched without sound, Digiday, 17.05.2016.
  Quote: As much as 85 percent of video views happen with the sound off, according to multiple publishers.
• Marcus, Jorien: De grootste valkuilen voor ondertitelaars, Stichting Hoormij, Onze Taal, 2019 - 9.
• Ondertiteling voor doven en slechthorenden, DigiToegankelijk (no date; accessed on 06.09.2024).
  This page explains the difference between subtitles (for translation) and subtitles for the Deaf and hard of hearing and the difference between closed and open captions.
• Lezersvraag: Hoe werkt ondertiteling?, Doof, 25.11.2021.
• In de media: ondertiteling voor doven en slechthorenden moet sneller verbeteren, Iederin, 11.04.2023.
• Meijer - Harrison, Claire: De digitale (on)toegankelijkheid van ondertiteling, Digitaal Toegankelijk, 08.03.2021.
• Why You Need to Add Captions and Subtitles to Video Apps, Rev, 05.09.2019.
• 3 New Improvements to Captions! (Creator Insider on YouTube, 2 minutes, 08.10.2021, Creative Commons Attribution licence).
• Tran, Stella; Shao Chieh Lo: 11 Free Tools to Make Your Video Captioning Process Easier!, Amara.org blog, 2018; updated on 25.08.2020 (accessed on 06.04.2021).
• Free Caption Converter Tool, 3PlayMedia, 04.10.2017, updated on 30.09.2020).
• Caption It Yourself, Described and Captioned Media Program (DCMP) (no date; accessed on 11.04.2022).
• sous-titres: Liste des outils pour sous-titrer vos vidéos et podcasts, emma11y (GitHub) (accessed on 10.05.2022).
• Bolnick, David: Synchronized Accessible Media Interchange Format: Closed Captioning & Audio Descriptions: preview of a description of the SAMI format for subtitles, submitted to the W3C's Web Accessibility Initiative in 1997 or 1998. (Accessed on 29.06.2022.)
• Understanding SAMI 1.0, Microsoft Docs, October 2001, updated in February 2003 (accessed on 29.06.2022).
• Synote: a web-based video and audio annotation tool (jiscsoftwarehub on YouTube, 12 minutes, 06.09.2013).
  Professor Mike Wald of the University of Southampton explains the goals and benefits of Synote and how it differs from lecture capture tools. Video description: Dr Mike Wald was the principal investigator in the development of Synote, an open-source web-based video and audio annotation tool. Dr Mike Wald talks to us about the drawbacks associated with lecture capture systems, the benefits of using transcription and annotation software and the development of Synote. Synote is a piece of open source software developed by the University of Southampton using funding from Jisc. It has won awards, including the Times Higher Education Outstanding ICT Innovation Award. (The video has closed captions.)

Examples of videos with captions or subtitles

• Strategy for the Rights of Persons with Disabilities 2021-2030 (European Commission on YouTube, 2:03 minutes, 03.03.2021).
  This video has closed captions in 25 languages.
• Elements and goals of the European Disability Strategy - Easy to understand (Inclusion Europe on YouTube, 2:21 minutes, 05.04.2023).
  This video has closed captions in English. There is also a link to a transcript.
• Do The Numbers On Toaster Dials Mean Minutes? (Tom Scott on YouTube, 2 minutes, 09.12.2014).
  This video has closed captions in 24 languages (including the auto-generated captions). Strictly speaking, these are just subtitles translated into many other languages: the speakers are not identified and non-speech sounds are not transcribed.
• how I studied for 12 hours a day for over a year (James Scholz on YouTube, 20 minutes, 18.04.2021).
  This video has subtitles in 12 languages (including the auto-generated English subtitles).
• The Lock Picking Lawyer (Vala Secure on YouTube, 98 seconds, 18.06.2020).
  A short video with open captions (one line per caption block).
• Fernsehen für alle - Untertitel machen es möglich! (ARD DIGITAL ERKLÄRT on YouTube, 6 minutes, 06.08.2020).
  This video uses open captions without speaker identification.
• Deutsch lernen mit Videos | Er ist der Größte | mit deutschen Untertiteln (Deutsch lernen mit der DW on YouTube, 5:21 minutes, 06.09.2023).
  This video uses closed captions without speaker identification or a description of non-speech sounds.
• YouTube Untertitel: Professionelle Untertitel ohne Fehler - Untertitelservice, Untertitelübersetzung (Erwin Lammenett Marketing-Problemlöser on YouTube, 4:30 minutes, 06.12.2020).
  This video uses closed captions without a description of non-speech sounds. A short section of the video uses open captions.
• Untertitel im Fernsehen | Fingerzeig (ALEX Berlin on YouTube, 28:18 minutes, 28.04.2017).
  This video is a conversation in sign language. A spoken version of the conversation is made available by measn of voice over; the voice over has closed captions.
• Gehörlos auf einer "normalen" Schule (SAT.1 REGIONAL on YouTube, 4:35 minutes, 05.10.2020).
  This video has open captions but the line length is often too long.
• "Die letzte Lüge" - OFFIZIELLER KINOTRAILER FÜR GEHÖRLOSE (ResisteFilm on YouTube, 2:30 minutes, 19.03.2011).
  This video has open captions including transcriptions of non-speech sounds and (occasionally) speaker identification.
• The Two Ronnies - Mastermind Sketch (Classic British Comedy on YouTube, 3:06 minutes, 15.10.2021). Video with open captions.

Transcripts

• Access – A Short Film About Accessibility: a video that has both audio description and links to alternative versions: a descriptive transcript, an MP3 audio version and closed captions (in WebVTT format).
• The Audio Issue. Quote: This is a Descriptive Transcript designed to provide access for all readers to the full contents—audio, image, and text—of McSweeney’s 64: The Audio Issue.

Audio Description

Audio description refers to a type of narration used to provide information about essential visual elements in a video for the benefit of visually impaired users. Audio description is usually inserted in pauses in the dialogue, and the resulting audio-described video is then offered as an alternative to the default version. In instructional videos and tutorials, it is often possible to avoid the creation of a separate video by making sure that all the essential visual information is narrated in the original version of the video. The Web Accessibility's tutorial on video content calls this “integrated description”; the American Council of the Blind calls this “embedded described video&rquo;.

• Audio Description of Visual Information, Web Accessibility Initiative (WAI), W3C (no date).
• What is Audio Description? (RNIB on YouTube, 2 minutes, 17.07.2018).
• The Standards, Audio Description Solutions.
  This is a page from which you can download the audio description standards formulated by the Audio Description Coalition in the USA. The document dates from 2009 (third edition) and covers general guidelines, guidelines unique to live description, guidelines unique to dance description, guidelines unique to opera description, guidelines unique to film and video description, guidelines unique to museum and exhibit description and a code of professional conduct.
• Audio Description, Accessibility by Design, Colorado State University (no date).
• Description Key - How to Describe, Described and Captioned Media Program (DCMP (no date).
• Lewis, Whitney: How to create audio descriptions for accessible YouTube videos, Pope Tech Blog, updated on 24.05.2024.
• Amboy, Dayna: Why You Need Audio Descriptions to Make Online Course Videos Accessible, TechSmith Blog, 04.06.2019.
• The Ultimate Guide to Audio Description, 3Play Media, 02.11.2018, updated on 03.02.2021 (accessed on 23.03.2021).
• Edelberg, Elisa: The Best Online Video Players for Audio Description, 3Play Media Blog, 18.01.2019, updated on 24.02.2020.
  This blog post discusses Brightcove, Vidyard, Ooyala, Kaltura, Able Player, OzPlayer and Wistia.
• WCAG confusion around audio description, Vision Australia, 30.07.2019.
• Advisory technique H96: Using the track element to provide audio descriptions, Techniques for WCAG 2.1.
• Rubin, Jonathan; Leisinger, Ryan; Morin, Gary: 508 Accessible Videos – How to Make Audio Descriptions, Digital.gov, 30.06.2014.
• Audio Descriptions Using Video Editing Software (Access Mooc on YouTube, 3 minutes, 29.01.2016).
  This video describes the basic steps for the creation on an audio described video by adding an extra audio track to the video. The demonstration uses Adobe Premiere Pro, but the steps also work with other video programs such as Camtasia Studio.
  1. Research best practices for creating audio descriptions.
  2. Using that research, write a script for the audio description.
  3. Record the audio descriptions using a good-quality microphone.
  4. Save the recordings as an audio file, for example in MP3 format.
  5. Import both the video file and the audio file into the video editing software.
  6. Add the video to one timeline and the audio to a different timeline.
  7. Synchronise the audio with the video (and make any other edits that may be necessary, such as lowering the volume of other audio in the video).
  8. Export the combined video and audio tracks as a new video file in a video format such as MP4.
• Audio Description in a Couple Minutes (Rooted In Rights on YouTube, 2 minutes, 22.07.2019).
  This video briefly explains what audio description is and gives a few recommendations about what to narrate in an audio description:
  1. Content that needs to be narrated includes all text that appears on screen, such as title cards and lower thirds.
  2. If applicable to your video, it is a good idea to let speakers introduce themselves. This makes it easier for listeners to identify and differentiate between the speakers throughout the video.
  3. Describe scenes that aren't heard.
  4. As a general tip: listen to your videos with your eyes closed to check what vital information you are missing.
• The Audio Description Project, American Council of the Blind (no date; accessed on 23.03.2021).
  See for example, EDV: Embedded Described Video.
• Audio Description Resource Guide, National Library Service for the Blind and Print Disabled (Library of Congress), 2018.
• Vorgaben für Audiodeskriptionen, Norddeutscher Rundfunk, 25.06.2019.
• Was ist Audiodeskription? (audiodekriptive Version für Sehbehinderte) (SwissFootballLeague on YouTube, 3 minutes, 19.10.2017).
  In this unususal example, the audio description is inserted before the start and at the end of the video.
• How audio descriptions help the visually impaired enjoy movies (Soutch China Morning Post on YouTube, 4 minutes, 08.07.2018).
  This short video is about audio description in cinemas in Hong Kong. It contains excerpts from interviews both with a blind cinema goer who lost her sight due to retinitis pigmentosa and with an audio describer.
• "Not Much To See": How the Blind Enjoy Movies (Academy Originals on YouTube, 4 minutes, 19.05.2014).
  This video contains excerpts from an interview with a blind person explaning why they go to the cinema and an example of audio description from an Indiana Jones film.
• Audiodeskription im ORF (mabacherTV on YouTube, 10 minutes, 22.11.2017).
  This video is about the audio description for sports programs at the Austrian broadcaster ORF. In contrast with audio description for films, this is not a description that supplements the standard audio track but replaces it. However, the video explains very well why audio description is important for people with visual impairments and what audio describes need to be capable of.
• Kleege, Georgina; Wallin, Scott: Audio Description as a Pedagogical Tool, Disability Studies Quarterly, Vol 35, No 2 (2015).
  This article is about audio description as an exercise that develops students' writing and critical thinking skills.
• Naber, Helmut: Warum Audio-Transkription wertvollen SEO-Content birgt, AudioTyped, 16.07.2020.
• Transkription – Verfahren und Produktionsablauf, zappmedia (no date; accessed on 03.05.2021).
  This article points out that the use of voice recognition has so far not been helpful Versuche, die aufwendige Transkriptionsarbeit durch den Einsatz von automatischer Spracherkennungssoftware zu erleichtern, haben bislang keine zufriedenstellenden Ergebnisse gebracht. Wenn diese auch bei langsam und bewusst gesprochenen Diktaten herangezogen werden kann, versagt sie in aller Regel bei dialogischen Szenen. Darüber hinaus bietet sie natürlich auch keinerlei Möglichkeit, für Hörbehinderte wichtige Informationen wie eine dramaturgisch bedeutsame Umgebungsbeschreibung, einen bestimmten Gesichtsausdruck oder die Schilderung wichtiger Geräusche herauszufiltern und schriftlich zu fixieren. Die Gewährleistung der Barrierefreiheit in der Transkription ist also nach wie vor nur durch manuelles Transkribieren von geschulten Fachleuten zu erreichen.
• Audiodeskription-Angebote in der ARD, Das Erste (no date; accessed on 21.10.2021).
• Richtlinien für die MDR-Audiodeskription, MDR, december 2018.
• Transcriptie richtlijnen, Amberscript, 04.06.2021; last updated on 24.06.2021.
• Add an audio track to your video, YouTube Help (no date; accessed on 25.10.2021).
• Audio Description in 360° videos, Immersive Accessibility (project) (no date; accessed on 08.04.2022).
• Fryer, Louise: An Introduction to Audio Description: A Practical Guide. Routledge, 2016. (212 pages) ISBN 9781138848177.
• Taylor, Christopher; Perego, Elisa (editors): The Routledge Handbook of Audio Description. Routledge, April 2022. (666 pages) ISBN 9780367434199.
• 1.2.3 / 1.2.5 Audio description - right language required? · Issue #3873, w3c/wcag on GitHub, issue submitted on 22.05.2024.
  See especially Mike Gower's comment from 3 June 2024, which lists several success criteria where the language of text-based alternatives or other textual content is not specified in the normative content of WCAG 2.
  Steve Faulkner on LinkedIn in June 2024: Video spoken language is English, transcript in Klingon, a WCAG fail?
• Video giants like YouTube and Vimeo are letting us down, Scribely blog, updated on 14.11.2024.

Audio Description via WebVTT

• WCAG Technique H96: Using the track element to provide audio descriptions, WCAG 2.1 Techniques (World Wide Web Consortium) (no date; accessed in October 2023).
• Audio description via VTT track, read by screen readers, Able Player Demos (no date; accessed in October 2023).

YouDescribe

• YouDescribe: a free online tool for adding audio description to YouTube videos. As of 2020, you can only log in to YouDescribe with Google.
• How to Audio Describe a YouTube Video, Media Access Australia, 27.10.2014.
  This page provides short instructions for using YouDescribe.
• Rodas, Julia Miele: YouDescribe: Testing Crowd-sourced Video Description for Service Learning at the City University of New York, The Journal of Interactive Technology and Pedagogy, 22.12.2015.
• Accessibility AD YouDescribe (ADA30Idaho on YouTube, 13 minutes, 19.10.2020).
• Veroniiiica: How to Create Audio Description for YouTube with YouDescribe, Perkins eLearning, 03.10.2019.

Examples of videos with audio description

• We're The Superhumans | Rio Paralympics 2016 Trailer: audio-described video by Channel 4. (Captions can also be activated. There is also a version without audio description.)
• Frozen - Trailer with Audio Description (IMSTVUK on YouTube, 2 minutes, 12.11.2013).
• Harry Potter, Deathly Hallows ~ Audio Description (DVD EXTRAS - By Vincent Corani on YouTube, 3 minutes, 24.04.2018).
  This is an audiodescribed version of the opening sequance and a scence from the film Harry Potter and the Deathly Hallows – Part 2 (2011).
• The Hunger Games with audio description: Katniss hunting ( Centre for Inclusive Design on YouTube, 1 minute, 28.10.2012).
• Out of Sight (with audio description) (Mirabai Knight on YouTube, 5 minutes, 16.11.2010).
  The description below the video says: This is an audio described version of Out of Sight, an animation by Ya-Ting Yu, Ya-Hsuan Yeh, and Ling Chung, three students at the National Taiwan University of the Arts. English audio description is by Mirabai Knight. It is intended only to provide access. No profit is made by it, and no copyright infringement is intended. (…)
  See also the blogpost NatCapVidMo Day 16: Out of Sight (With Audio Description!) (16.11.2010), whic contains the transcription of the audio description.
• Popeye | Fright to the Finish with Closed Captions and Audio Description (VITACCaptions on YouTube, 6 minutes, 23.10.2012).
• The Interviewer - Captions & Audio Description (Bus Stop Films on YouTube, 13 minutes, 18.01.2015).
• Sci-Fi Short Film “How To Be Human” Audio Description Version (DUST on YouTube, 19 minutes, 22.11.2019).
  This is an example of “immersive audio description” in which the description is spoken by one of the film's characters. The description below the video says This inclusive version of "How To Be Human" includes an audio description for individuals with visual impairment. If you were forced to flee your own war-ridden country, would you sacrifice what makes you human to survive? "How to be Human" by Bruno Centofanti.
  The original version Sci-Fi Short Film “How To Be Human” is 14 minutes long, i.e. six minutes shorter. This is because the version with audio description begins with a six-minute narration that provides the story's background and presents the two main characters.
• Was ist eigentlich ein Hackathon? (Audiodeskription) (Aktion Mensch on YouTube, 39 seconds, 30.12.2016).
• I challenge you: Die Gaming-Challenge (Audiodeskription) (Aktion Mensch on YouTube, 13 minutes, 21.08.2017).
• Haifischwelt im Thüringer Wald (mit Audiodeskription) | Der Osten - Entdecke wo du lebst (MDR Mitteldeutscher Rundfunk on YouTube, 44 minutes, 23.04.2020).
• HR-Tatort "Wer bin ich?": Audiodeskription (diana gaul, sprecherin on YouTube, 4 minutes, 26.01.2016).
  This example displays a static image instead of a video.
• BR-Tatort Macht und Ohnmacht: Audiodeskription (diana gaul, sprecherin on YouTube, 3 minutes, 28.08.2013).
  This example displays a static image instead of a video.
• Prince Of Persia Audio Described (AD) Trailer (IMSTVUK on YouTube, 2 minutes, 29.05.2021).
• Communication Technology for Persons Who Are Deafblind (Perkins School for the Blind on YouTube, 22 minutes, 10.07.2014).
  Description below the video: In this webcast, Jerry Berrier provides an overview of a variety of communication technologies for individuals who are deafblind. Jerry presents a historical view of different devices that have been used in the past and compares them with the technology that is available today.
• How Haben Girma Became Harvard Law School’s First Deafblind Grad (CNBC Make It on YouTube, 7 minutes, 04.01.2020).
• Audio description (extended) (WCAG 1.2.5) (eLaHub on YouTube, 30 seconds, 19.04.2019).
• Barrierefreiheit für Blinde und Gehörlose - mit Audiodeskription (unserkanal on YouTube, 3:13 minutes, 25.05.2015).

Resources That Cover Both Captioning and Audio Description

• Ernst, Jules: YouTube embed, WCAG compliant, 200 OK - Jules Ernst, 09.03.2022.
• Henry, Shawn Lawton: Transcripts on the Web, uiAccess, 2019 (accessed on 21.10.2021).
• Adding captions and subtitles to HTML5 video, MDN Developer guides (no date).
• Accessible Multimedia, Learn Web Development, MDN (no date).
• How to Add Closed Captions and Audio Description to OzPlayer, 3Play Media (no date).
• Creating Accessible Videos, University of Washington (no date).
• Description Key: Guidelines and Best Practices for Describing Educational Video.
• Barrierefreie Lehrvideos, E-Learning Koordinierungsstelle, FH Dortmund (no date; accessed on 11.05.2021).
• Leitfaden barrierefreie Online-Videos, BIK für Alle (no date; accessed on 08.04.2022).
• de Cuba, Darice: Captions and transcripts, the budget says no, darice.org, 27.01.2022.

Video or Audio Players

• Able Player. According to the description on the website, Able Player is a fully accessible cross-browser media player. It uses the HTML5 <audio> or <video> element for browsers that support them, and (optionally) the JW Player as a fallback for those that don’t. (JW Player is available under various pricing models.) It also supports YouTube videos (if you provide a YouTube Data API key). For captions, it supports the WebVTT format. Audio descriptions are supported either using the VTT format (i.e. a text-based file) or by providing an extra video file: When two videos are available (one with description and one without), both can be delivered together using the same player and users can toggle between the versions. (Accessed 12.02.2021.)
  See also Able Player's source code repository on GitHub. The code is available under the MIT licence.
• Video.js is another video player in JavaScript that has many accessibility features. The main version is for playing video files. For YouTube videos, you will need the plugin videojs-youtube. For Vimeo videos, you will need the plugin videojs-vimeo. Video.js itself is available under the Apache License 2.0; the two plugins are available under the MIT License. The Described Video plugin for videojs adds a button to the Video.js player that allows users to switch between different versions of a video.
  See also the blog posts Feature Spotlight: Accessibility by Brandon Casey (Video.js Blog, 2017), Video.js's Approach to Video Player Accessibility (3PlayMedia blog, 30.04.2015, updated on 03.06.2019), How to Add Captions, Subtitles, and Interactive Transcripts in Video.js (3PlayMedia blog, 20.07.2015, updated on 05.01.2018) and Video.js issue #7490: Subtitles not working (October 2021).
  Video.js is the video player integrated into Moodle 4.0.
• Plyr: A simple, accessible HTML5 media player by @sam_potts from @selz. This is a player for both video files and for videos streamed from YouTube or Vimeo. For captions, it supports the VTT format. See the source code repository on GitHub. The code is available under the MIT licence.
• Paella Player, the multistream player for lectures. According to the website, Paella Player is an Open Source Javascript video player capable of playing an unlimited number of audio & video streams synchronously, Live Streaming, Zoom, Captions, contributed user plugins and a lot more. It is easy to install and customize for your own needs. (Accessed on 28.04.2021.)
  See also the Paella Player GitHub repository.
• PayPal: Accessible HTML5 Video Player. It requires direct links to video files; it does not work with links to YouTube or Vimeo videos. For captions, it supports the VTT format. For audio description, it appears to provide support only through a VTT descriptions track (see pull request #125: Multiple Text Track Support). The code is available under the BSD 3-clause licence.
• Universal Video Player is an accessible video player with support for captions and screen reader accessibility. The code has not been updated since 2016.The site had a security issue on 25.04.2022 and 10.05.2022.
• Nomensa: Accessible Media Player. The code is available under the GPL version 3 licence but has not been updated since 2015. (Accessed 12.02.2021.)
• Christian Heilmann: Making YouTube easier and more accessible (updated 12/06) (originally published on 12.06.2008): blog post about a YouTube player that is easier to use for people with learning disabilities. Note that all of the links to the domain icant.co.uk are now out of date. Instead, check the code repository easy-youtube on GitHub. The code is available under the BSD 3-clause licence.
• Raghavendra Satish Peri: Accessible HTML5 Media Players & More, Digital A11Y, 16.04.2018.
• Web-Based Media Player Accessibility Comparison Table (“source code” on GitHub).
  See also: Committee on Institutional Cooperation Information Technology Accessibility Group (ICI ITAG): Media Player Accessibility Comparisons: spreadsheet on Google Sheets. This version is no longer being maintained.
• Adrian Roselli: Fixed: Inaccessible YouTube Embeds, 13.08.2017, updated on 07.09.2017.
• Wild, Gian: The Inaccessibility of Video Players, International Conference on Computers Helping People with Special Needs (ICCHP) 2018.
  Results of a series of tests of 37 major video players, including YouTube embed, Vimeo, JW Player, Plyr and Video.js; only AblePlayer and OzPlayer pass all the tests.
• Ken Petri: Web-Based Media Player Accessibility Comparison Table, kensgists on GitHub Pages. Last updated in 2016. (See the GitHub repository apt.)
• What video players/sites are fully accessible? A question posted on User Experience Stack Exchange in January 2011; the answer posted in in 2011 Easy YouTube, which is no longer being maintained, and the Vimeo player.
• Asyush: 15 Best HTML5 Video Players in 2021, All Tech Nerd, 06.09.2020.
  This article lists VideoJS, JW Player, Media Element.js, Video for Everybody, Kaltura HTML5 Video Player, Plyr, Elite Video Player, Ultimate Video Player, jPlayer, Elmedia Player, Chameleon HTML5 Video Player with Flash Backup, Afterglow and the WordPress plugins Videojs HTML5 Player, Video Embed & Thumbnail Generator and FV Flowplayer Video Player.
  Accessibility is not used as a selection criterion for the players; accessibility is only mentioned in the presentations of JW Player and Plyr.
• Strongin, Daniel: 15 Best HTML5 and JavaScript Video Players (+5 Best Free Players), EnvatoTuts, 12.08.2020.
  This list is very similar to the list on All Tech Nerd.
• Mattison, Ollie: 10 open source video player for Linux, Windows and Mac, Filmora, 25.06.2021.
  This article lists the following players: VLC, Miro, MPV, Banshee, Audacious (an audio player), Kodi, Apprentic, FFmpeg, SMPlayer and Xine. Accessibility is not used as a selection criterion.
• Accessibility with THEOplayer, THEOplayer, 07.01.2020.
  See also the page Together for Rights: the Strategy for persons with disabilities at the European Commission's Directorate General “Employment, Social Affairs & Inclusion” for an example of THEOplayer. The video embedded in that page has subtitles or captions in the European Union's 24 official languages, audio description in the same languages, sign language (looking like picture-in-picture video), options to change the video speed and the display of subtitles.

Transcribing Audio

• oTranscribe: A free web app to take the pain out of transcribing recorded interviews.
• Myers, Erin: 10 Essential Tools to Record, Edit, Transcribe and Share Podcasts, Temi.com blog, 25.09.2017. (This blog post was not written with accessibility in mind but mentions some useful tools.)
• Lewis, John: 5 Free Transcription Software for Triumphant Transcripts, Transcriptionstar blog, 13.07.2017.

Sign Language

• Gebärdensprache - ARD, Das Erste, 17.09.2019.
• Informationen zur GebärdenSchrift, delegs (no date; accessed on 21.10.2021).
• Verbundprojekt AVASAG: Sechs Partner entwickeln Avatar für Gebärdensprache, UEPO.de, 10.05.2020.
• von Pappenheim, Cornelia: Warum Gebärdensprach-Avatare nicht die Überhand gewinnen sollten, GMU – Gehörlosenverband München und Umland, 05.07.2019.
• Gerardo, Benedikt Sequeira: GMU: Sind Avatare die ideale Lösung?, Taubenschlag, 14.02.2022.
• Interkulturelle Kompetenz, Vibelle, (no date; accessed on 29.09.2022).
  Example of a page on which a link to a sign-language video is available.

Avoiding Photsensitive Epilepsy

• Photosensitive Epilepsy Analysis Tool (PEAT), Trace Research & Development Center, 11.12.2020.
• Cambridge Research Systems Ltd Whitedot Scientific Ltd: this company offers HardingFPA, mainly for broadcasters and digital media producers.

The video Element's poster Attribute

HTML5 does not define a mechanism to provide a text alternative for the image referenced by the poster attribute.

• Foliot, John: Text description for @poster (was RE: CP, ISSUE-30: Link longdesc to role of img [Was: hypothetical question on longdesc]), public-html@w3.org Mail Archives, 24.03.2012.

Content Readability

• DuBay, William H.: The Principles of Readability (PDF), 2004.
• Mikk, Jaan: Methods for determining optimal readability of texts, Journal of Quantitative Linguistics, Volume 2, Issue 2 (1995; abstract).
• Cannon, Barbara; Edmond, Grace: A Few Good Words Using Core Vocabulary to Support Nonverbal Students, The Asha Leader, Vol. 14 (April 2009): 20-23. (Accessed on 14.07.2021.)
• Scott, Brian: Readability Formulas: page that lists many readability formulas for English. Brian Scott is a freelance writer.
• Simple English Wikipedia: List of readability tests.
• For readability analysis in R, see the package koRpus:
  • Package ‘koRpus’ (documentation).
  • Using the koRpus Package for Text Analysis (17.05.2021).
• For readability analysis in Python, see the package textstat (part of Pypi; see also the textstat GitHub repository).
• Basu, Saikat: 8 Readability Web Tools to Test Your Writing Quality, MakeUseOf, 10 March 2010.
• The Up-Goer Five Text Editor: web-based tool where you can enter text and check whether it uses only the 1,000 most common English words. The tool's name is inspired by the XKCD cartoon Up Goer Five, which tried to explain the component parts of a space ship or rocket using only the 1,000 most common English words. See also Randall Munroe's blog post A Thing Explainer word checker (22 September 2015) and his Simple Writer.

See also Frequency Lists and Corpora.

E-Books, Audio Books and ePub

ePub

• EPUB Accessibility 1.0: Conformance and Discovery Requirements for EPUB Publications, Recommended Specification 5 January 2017, International Digital Publishing Forum (IDPF), 05.01.2017.
• EPUB Accessibility 1.1: Conformance and Discoverability Requirements for EPUB Publications, W3C.
• Accessible Publishing Best Practices: Guidelines for Common EPUB Issues in Plain Language, AccessiblePublishing.ca (no date; accessed on 28.10.2021).
• Creating Accessible Publications with EPUB, National Center on Accessible Educational Materials (no date; accessed on 05.11.2021; Creative Commons Attribution-ShareAlike 4.0 International License).
• Ace, by DAISY: an open-source accessibility checker for EPUB.
• Brady, Laura: Producing Accessible Ebooks, EPUBSecrets, 20.06.2017.
• WordToEPUB, The DAISY Consortium (no date; accessed on 05.11.2021).
  WordToEPUB is a tool for Microsoft Word and Windows. The page contains a link to WordToEPUB version 1.07, which was released on August 2021.
• Getting started with WordToEPUB, The DAISY Consortium (no date; accessed on 05.11.2021).
• What is EPUB?, EDRLab (no date).

LibreOffice Writer has a built-in ePub export function. In LibreOffice 7, this export function does not create accessible ePub files. For example, alternative texts for images are not preserved but replaced with a file path, headings are not exported using HTML heading tags and lists are not exported using HTML list elements.

• Glazman, Daniel: LibreOffice and EPUB, Glazblog, 01.02.2018. LibreOffice 6 introduced an ePub export feature (which previously required an extension such as Writer2ePub). For background information, see the blogpost Basic EPUB3 export in Libreoffice (10.11.2017). Daniel Glazman reviews the XHTML and CSS code exported by this initial implementation.
• Marge: E-boeken maken met LibreOffice 6.0, In de kantlijn, 15.04.2018.

Other E-Book Resources

• It’s Time to Use the Modern Digital Publishing Format for Your Organization’s Documents, The DAISY Consortium, 10.09.2020 (white paper available under a Creative Commons licence)..
• Digital Publishing WAI-ARIA Module 1.0: W3C Recommendation 14 December 2017.
• Leveraging InDesign for Accessible EPUB Creation (W), Inclusive Publishing, 26.05.2020.
• Collinson, Simon: Ace by DAISY: An Essential Tool for the ebook Developer’s Workbelt, Inclusive Publishing blog, 29.01.2018.
• Maumet, Luc: Accessibility in reading systems: what about dyslexia?, EDRLab, 20.06.2017.
• Dobson, Victoria; McNaught, Alistair: Crowdsourcing e-book accessibility information and the impact on staff development, UKSG Insights, 30.2 (2017): pages 61–70. DOI: http://doi.org/10.1629/uksg.358.
• Spolanka: Accessibility and eBooks – Resources and an Interview, No Shelf Required, 06.10.2010 (accessed on 14.07.2021).
• Roncevic, Mirela: Making digital resources accessible for students with disabilities: Are libraries, publishers, and vendors ready for the new rules and regulations? No Shelf Required, 29.06.2020 (accessed on 14.07.2021).
• Adding accessibility enhancements to EPUB files - ATN webinar series (DAISY Consortium on YouTube, 59 minutes, 12.06.2019).
  For more info about this webinar series, see EPUB Webinar Series.
• Create EPUB publications from Word with a simple tool anyone can use (DAISY Consortium on YouTube, 56 minutes, 21.04.2020).
  (This includes a demo of WordToEPUB.)
• A Crash Course in Ebook Accessibility Introduction: The Benefits of EPUB (NNELS Canada on YouTube, 7 minutes, 20.04.2020; Creative Commons).
• Common Accessibility Issues in EPUB Files (NNELS Canada on YouTube): playlist of 5 short videos.
• Thorium Reader, EDRLab (no date; accessed on 26.10.2021).
  A free and open-source ePub reader with several accessibility features. The software is available for Windows, Mac OS and Linux. See also the Thorium Reader repository on GitHub.

Benefits of Accessible Video

• Iglesias, Violaine: Beyond the mandates: The far-reaching benefits of multimedia accessibility, Learned Publishing, Volume 31, Issue 1 (18.01.2018; free access).
• Dillman, Austin: How Captions Benefit More Than the Deaf and Hard of Hearing, Rev, 21.06.2017.
• Leduc, Jaclyn: Disabilities Directly Impacted by Accessible Video, 3PlayMedia blog, 23.12.2020.
• Garman, Judith: Autistic spectrum, captions and audio description, Mindful Research, 29.08.2011.
• Captions and audio description benefit people on the autism spectrum, Media Access Australia, 16.09.2011.
  This article is based on Judith Garman's blogpost.

Mathematics, Equations and STEM Accessibility

• Accessible Equations, University of York (no date; accessed on 01.10.2021).
• Solutions for the Accessibility Community, Design Science (no date; accessed on 01.10.2021).
• Teaching with Accessible Math, National Center on Accessible Educational Materials at CAST (no date; accessed on 01.10.2021).
• Creation of Accessible Mathematic Equations, California State Polytechnic University, Pomona, (no date; accessed on 01.10.2021).
• Equations: MathML, Images and LaTeX, Accessibility at Penn State, (no date; accessed on 01.10.2021).
• Gillen, Mary: ACCESSIBLE PDFs: How to Make Math Formulas Accessible to Screen Readers, accessible-website-services, 30.09.2020.
• Sian, Damian: MathML for Accessible Math Markup, Digital Accessibility, Princeton University, 24.03.2017, 01.02.2018.
• Creating Accessible Equations in MS Word, UCF (no date; accessed on 01.10.2021).
• Cheyann: How to Make Accessible Math and Science, Accessibility Toolkit, 11.12.2018 (Creative Commons).
• Accessible Math Equations with NVDA, MathPlayer and Firefox (ZAccess on YouTube, 10 minutes, 02.12.2021).

Other Links

• Inclusief Publiceren: website created by a consortium of organisations in the Netherlands.
• Putland, Matthew: Embedded YouTube and Google Maps – are they accessible?, Vision Australia, 01.05.2020.
• Make your Outlook email accessible, Microsoft: Office Support (no date).
• Aron, Jacob: Crowdsourcing can serve up the subtitles to your life, New Scientist, Volume 215, Issue 2874, 21 July 2012, Pages 21.
• Netflix to use crowd-sourced captions, Media Access Australia, 8 August 2012.
• Nam, Tammy H.: The Sorry State of Closed Captioning, The Atlantic, 24 June 2014.
• Straumsheim, Carl: Berkeley Will Delete Online Content, Inside Higher Ed, 06 March 2017.
  The University of California at Berkeley had more than 20,000 online audio and video files. Since these are not accessible to people with disabilities due to the lack of captions, screen reader compatibility and other issues. Instead of making the content accessible, the university decided to remove the content from public view.
• Rowland, Cyndi: UC Berkeley Decision Results in Universal Inaccessibility, WebAIM blog, 10 March 2017.
  Since the accessibility requirements (e.g. captions) predate the creation of the content that is being withdrawn, Cyndy Rowland writes: Berkeley, America’s number one public university, a pioneer in social justice, civil rights, and disability rights, has little excuse for these careless decisions.
• Born Accessible Publishing, DIAGRAM Center (no date).
• ICADD SGML: International Committee for Accessible Document Design. (Copy of a document from 1992; only of historical interest now. See also the Information Technology and Disabilities Journal, Volume II, Number 2, May 1995.)
• Barrierefreie Angebote im Ersten, Das Erste, 20.08.2019.
  This article claims that in 2018, close to 98% of the channel's broadcasts had captions: Insgesamt waren 2018 knapp 98 Prozent des Angebots im Ersten mit Untertiteln versehen. Close to 52% of broadcasts in 2018 had audio description: Für knapp 52 Prozent des Hauptabendprogramms im Ersten gab es 2018 eine Audiodeskription, vor einem Jahr waren es nur knapp 50 %.
• ZDF-Filme sind Hörerlebnisse, ZDF Presseportal, (no date, possibly 2019).
• Methods to produce flexible and accessible learning resources in mathematics, Maths & Stats Help Centre, University of Bath, 2012 (Creative Commons licence).
• Reading Sounds | Closed-Captioned Media and Popular Culture: supplemental website for the book Reading Sounds by Sean Zdenek. This site caused a security warning on 25.04.2022.
• Guidance: Visually impaired and hearing impaired audiences, BBC: Editorial Guidelines, last updated in March 2021.
• Access services at the BBC, BBC (no date; accessed on 21.10.2021).
• Channel 4 subtitles and other services not likely to return until mid-November, BBC, 19.10.2021.
• Mager, William: See Hear: Mandela and 'bogus' signer, BBC, 12.12.2013.
• Smart caption glasses, National Theatre (no date; accessed on 22.10.2021).
  Quotes: When wearing the glasses, users will see a transcript of the dialogue and descriptions of the sound from a performance displayed on the lenses of the glasses. Smart caption glasses are the culmination of a 4 year collaboration between the National Theatre and speech and language experts led by Professor Andrew Lambourne.
• reveal-a11y: plugin for reveal.js for better slide accessibility. Created by Marcy Sutton. MIT licence.
• barrierefreies Kino mit Audiodeskription und Untertitel, Barrierefreies Kino und Inklusion mit Greta & Starks (no date; accessed on 22.10.2021).

Other resources and tips not directly related to accessibility:

• How to Record Screen using Microsoft PowerPoint (Kevin Stratvert on YouTube, 11 minutes, 03.05.2020).
• Galang, Anton: The 9 Best Open Source Video Editing Software of 2021, Lifewire, 16.09.2020.

Downloads

• Checkliste Barrierefreie Präsentationen (PDF): a single-page handout (in German) with a few selected accessibility guidelines for presentations with Microsoft PowerPoint (version 2016) or LibreOffice Impress (version 7).