Content Accessibility

The resources on this page are related to documents, audio and video, which may be found on websites, in other words, web resources that are not implemented using only HTML and CSS. For HTML-based web content, see the pages on Web Applications and Web Accessibility Tools.

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.

Microsoft Word

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

Microsoft PowerPoint

Other Microsoft Applications


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.

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.

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.

Other Applications (Including Google Docs)

Portable Document Format (PDF)

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

Accessible Tables in PDF

Accessible PDF Forms

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

Checking PDF Accessibility

Other PDF Tools

PDF Accessibility Standards and Background Documents

PDF Accessibility on Mac OS

Support for tagged PDF on Mac OS has long been poor:

Older Resources about Accessible PDF

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.

Audio and Video

Captioning Guidelines

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”.

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:

Possibly usable for transcribing audio:

Tutorials on Captioning

Articles on Captioning

Examples of videos with captions or subtitles


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 via WebVTT


Examples of videos with audio description

Resources That Cover Both Captioning and Audio Description

Video or Audio Players

Transcribing Audio

Sign Language

Avoiding Photsensitive Epilepsy

Content Readability

See also Frequency Lists and Corpora.

E-Books, Audio Books and ePub


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.

Other E-Book Resources

Benefits of Accessible Video

Mathematics, Equations and STEM Accessibility

Other Links

Other resources and tips not directly related to accessibility: