Accessibility Guidelines and Standards

Web Accessibility

• W3C: Web Content Accessibility Guidelines (WCAG) 2.1: W3C Recommendation 05 June 2018 See also the blog post WCAG 2.1 is a W3C Recommendation (5 June 2018) by Andrew Kirkpatrick, co-chair of the Accessibility Guidelines Working Group.
  Several other resources accompany WCAG 2.1:
  • W3C: Web Content Accessibility Guidelines (WCAG) Overview: this is a good starting point for people who are new to these guidelines.
  • W3C: Understanding WCAG 2.1.
    This is a guide to the guidelines in general and to each success criterion in particular.
  • W3C: Techniques for WCAG 2.1.
    This document explains how the success criteria can be implemented; it is not meant to be exhaustive: it is also possible to pass the success criteria with techniques that are not documented here.
  • W3C: How to Meet WCAG 2 (Quick Reference): A customizable quick reference to Web Content Accessibility Guidelines (WCAG) 2 requirements (success criteria) and techniques.
    This site allows developers to filter the techniques based on the conformance level and the technologies that apply to the content they are creating.
  
  Articles and blog posts:
  • Onsman, Ricky: What’s new in WCAG 2.1?, Intopia, 15.06.2018.
  • Avila, Jonathan: Does WCAG 2.1 Replace 2.0? When Should You Adopt WCAG 2.1?, Level Access, 27.06.2018.
  • Onsman, Ricky: Intopia Launches WCAG 2.1 Map, Intopia, 26.07.2018.
  • Lauke, Patrick: These aren't the SCs you're looking for ... (mis)adventures in WCAG 2.x interpretation and audits (Patrick Lauke on YouTube, 43 minutes, 04.01.2020).
    Video recording of a talk at #a11yTO Conf in Toronto, 24.10.2019. Patrick Lauke discusses a few success criteria that are often misinterpreted. For example SC 2.4.6 does not require that a web page contains headings or that labels need to be correctly associated with form controls. Success criterion 3.3.2 does not require that labels are correctly marked up using the label element or properly associated with from controls. Success criterion 2.1.1 does not contain requirements related to which specific keys need to be used to operate something. For example, a button emulated using an a element cannot be activated using the space bar, even though that is standard behaviour for a button, but would still pass SC 2.1.1. Success criterion 3.2.3 is about the order of the navigation in relation to the rest of the page. Success criterion 1.3.3 does not prohibit the use of colour, shapes etcetera in controls; however, instructions for using those controls must not exclusively rely on these characteristics.
    Patrick Lauke also discusses “cascades of fail”, i.e. when something fails several success criteria. For example, a link containing only an image without an alt attribute fails multiple success criteria. Auditors within the same organisation need to rate this consistently.
    WAG is not perfect. Some success criteria appear to be subjective. For example, what is “equivalent purpose” in SC 1.1.1? What is “conveyed by the presentation” in SC 1.3.1? What is descriptive enough for SC for 2.4.6?
    Some success criteria have loopholes. For example, what does “visible” mean in SC 2.4.7? According to the letter of the success criterion, a single pixel with a faint colour, would pass. WCAG 2.1 tried to patch loopholes by adding new SCs instead of modifying existing ones. SC 1.4.11 is meant to patch a loophole in SC 2.4.7, since it applies to the focus state of components, but a single pixel used as a focus indicator would still pass. It also does not cover the contrast between the focused and the unfocused state of controls. Failure F73 tries to close another loophole by redefining “colour” in non-normative text.
    Some success criteria are overly specific and apply only in very specific situations. For example, SC 1.4.10 (Reflow) is meant to help low-vision users who need to zoom in and should not need to scroll both horizontally and vertically, and also specifies a width in CSS pixels. SC 1.4.12 (Text spacing) is so specific that it does not always apply.
    See also the slides for “These aren't the SCs you're looking for…”.
  
  The following blog posts, articles and resources were written or created while WCAG 2.1 was still under development:
  • Kirkpatrick, Andrew: WCAG 2.1 is a Candidate Recommendation, W3C Blog, 30.01.2018.
    The Accessibility Guidelines Working Group is looking for implementations for each of the success criteria in WCAG 2.1 in order to move to the next stage in the standardisation process. Some of the new success criteria are “at risk”, which means that the Working Group is unsure if implementation testing or public review will validate those success criteria for the final guidelines. (Apparently, the Candidate Recommendation stage does not require at least two independent implementations but adequate implementation experience. The 2005 version of the W3C Process Document also said, The Working Group is not required to show that a technical report has two independent and interoperable implementations as part of a request to the Director to announce a Call for Implementations.)
  • McDonald, David: WCAG 2.1: The final list of candidate Success Criteria is here, CanAdapt, August 2017.
  • Roselli, Adrian: What’s New in WCAG 2.1, Adrian Roselli's blog, 23.08.2017.
  • Access42: Les nouveautés des WCAG 2.1, Access42, 10.08.2017.
  • Marchak, Erin: Usability and Accessibility: The new WCAG 2.1 and Nielsen’s 10 Usability Heuristics, Myplanet, 10.10.2017.
  • Sims, Glenda: Understanding WCAG 2.1 – Reviewing Low Vision Success Criteria, The Deque Blog, 14.12.2017.
  • Das Schicksal von "Target Size", Incobs, 01.02.2018.
  • Gower, Michael: Simplifying the New WCAG 2.1 Guidelines, IBM Age and Ability blog, 08.02.2018.
  • Garaventa, Bryan: Differences between ARIA 1.0 and 1.1: Changes to role="combobox", Level Access, 27.01.2017.
  • Experimental code related to personalised accessibility for cognitive impairments:
    • W3C Cognitive Accessibility Task Force: Easy Personalization.
    • coga.personalisation on GitHub.
  • Sims, Glenda: WCAG 2.1: What is Next for Accessibility Guidelines, Deque blog, 24.04.2018.
  • Rietveld, Rian: We need to talk about WCAG, Level Level Rotterdam, 18.05.2021.
    Dennis Lembrée tweeted this blog post, pulling out one specific quote: Stop adding new Success Criteria before the most recent ones have been properly documented, explained and better adopted into websites worldwide.
  • Sims, Glenda: Understanding WCAG 2.1: A History of WCAG, Deque blog, 01.11.2017.
  • Sims, Glenda: Understanding WCAG 2.1 – Reviewing Cognitive Success Criteria, The Deque Blog, 09.01.2018.
  • Mattes, Kurt: WCAG 2.1: Success Criteria for Cognitive Disabilities, The Paciello Group blog, 01.03.2018.
• W3C: Web Content Accessibility Guidelines (WCAG) 2.0 - W3C Recommendation 11 December 2008. (Translations of WCAG 2.0 e.g. Richtlinien für barrierefreie Webinhalte (WCAG) 2.0 and Règles pour l'accessibilité des contenus Web (WCAG) 2.0 (French).)
  
  Since the publication of WCAG 2.1 in June 2018, the older version of the guidelines is strictly speaking out of date, but since many resources are still based on the older version, a transition period will be necessary.
  Several other resources accompanied these WCAG 2.0:
  • W3C: Web Content Accessibility Guidelines (WCAG) Overview: this is a good starting point for people who are new to these guidelines.
  • W3C: Understanding WCAG 2.0: A guide to understanding and implementing Web Content Accessibility Guidelines 2.0.
    This is a guide to the guidelines in general and to each success criterion in particular.
  • W3C: Techniques for WCAG 2.0: Techniques and Failures for Web Content Accessibility Guidelines 2.0.
    This document explains how the success criteria can be implemented; it is not meant to be exhaustive: it is also possible to pass the success criteria with techniques that are not documented here.
  • W3C: How to Meet WCAG 2.0: A customizable quick reference to Web Content Accessibility Guidelines 2.0 requirements (success criteria) and techniques.
    This site allows developers to filter the techniques based on the conformance level and the technologies that apply to the content they are creating. This link now redirects to a version based on WCAG 2.1.
  • Viget: Interactive WCAG 2.0.
  • Wuhcag: WCAG 2.0 checklists: three checklists for levels A, AA and AAA, respectively. The checklists are also available as PDF files.
  • Pennsylvania State University: WCAG 2.0 Guidelines: summaries of the guidelines for Webmasters who may have some knowledge of HTML or programming.
  • Hentry, Herin: WCAG is not scary anymore - A progressive approach to Website Accessibility, LinkedIn Pulse, 25.07.2016.
  • Campbell, Alastair: Web accessibility guidelines and how to use them, Nomensa blog, 22.11.2017.
• Vanderheiden, Gregg C.; Chisholm, Wendy: Page Author Guidelines - Version 8: Unified Web Site Accessibility Guidelines, Web Accessibility Initiative (W3C WAI), 20.01.1998.
  This document was a precursor of the Web Content Accessibility Guidelines 1.0 (5 May 1999) and is listed here for purely historical reasons.
• Media Accessibility User Requirements: W3C Working Group Note 03 December 2015, World Wide Web Consortium.
  From the abstract: This document presents the accessibility requirements users with disabilities have with respect to audio and video on the web.
• CEN, CENELEC, ETSI: EN 301 549 V3.2.1 (2021-07): Accessibility requirements for ICT products and services (PDF). This document replaces older versions such as EN 301 549 V2.1.2 (2018-08): Accessibility requirements for ICT products and services (PDF) and EN 301 549 V1.1.2 (2015-04): Accessibility requirements suitable for public procurement of ICT products and services in Europe (PDF). Several chapters contain requirements that reference WCAG 2.1 success criteria. See also the announcement WCAG 2.1 Adoption in Europe on the W3C Blog (13.09.2018).
  The national standardisation bodies in some European member states provide translations of the European standard, for example, AFNOR's French translation, NF EN 301549 (435,88 € as of 09.01.2013), NBN's French translation (170 € as of 09.01.2023), UNE's Spanish translation and DIN EN 301549 Barrierefreiheitsanforderungen für IKT-Produkte und -Dienstleistungen.
  See also:
  • Latest changes to accessibility standard, Shaping Europe’s digital future (European Commission) (no date; accessed on 10.01.2023).
    This page lists the changes between v2.1.2 and v3.2.1 of EN 301 549, the requirements that are not in WCAG 2.1 and the requirements in EN 301 549 that are not relevant to the Web Accessibility Directive.
  • EN 301 549: videos about the standard created by Funka (sponsored by Microsoft) in 2017 and made available under the terms of a Creative Commons licence.
  • Human Factor TC / EN 301 549, ETSI GitLab (no date; accessed on 05.07.2022).
  • Learn about EN 301 549 from Funka, Accessible TechComm, July 2016.
  • Standard - EN 301 549: Accessible ICT Procurement Toolkit.
  • What is the European accessibility standard EN 301 549? (Deque Systems on YouTube, 12 minutes, 18.02.2019.
    This is an introduction to the standard presented as an interview with Shadi Abou-Zahra of the World Wide Web Consortium (W3C).
  • Norme NBN EN 301549:2021, NBN (no date; accessed on 16.12.2022).
• W3C: Accessible Name and Description Computation 1.1: W3C Recommendation 18 December 2018. This specification is targeted at user agent developers.
• W3C: Making Content Usable for People with Cognitive and Learning Disabilities: W3C First Public Working Draft 11 December 2018. Making Content Usable for People with Cognitive and Learning Disabilities: W3C Working Group Note 29 April 2021. This specification was developed by the Cognitive and Learning Disabilities Accessibility Task Force (Cognitive A11Y TF). See also the Cognitive Accessibility Roadmap and Gap Analysis.
• W3C: Authoring Tool Accessibility Guidelines (ATAG) 2.0: guidelines for tools that produce web content, such as WYSIWYG HTML editors, web content management systems, software for creating mobile web applications, and tools convert or export to web content. The guidelines are divided into two parts: Part A covers guidelines for the user interface of authoring tools, while Part B covers guidelines for the content produced with such tools.
• W3C: User Agent Accessibility Guidelines (UAAG) 2.0: guidelines for web browsers and similar applications (including media players and browser extensions) that render web content.
• W3C: Accessible Rich Internet Applications (WAI-ARIA) 1.1 — W3C Recommendation 14 December 2017.
• W3C: Accessible Rich Internet Applications (WAI-ARIA) 1.0: this was the first official version of a specification of an ontology of roles, states and properties that can be used to improve the accessibility of web applications.
  This document is part of a suite of documents. The best starting point is the WAI-ARIA Overview. For developers of web applications or widgets, the following documents are especially important:
  • WAI-ARIA 1.0 Primer: An introduction to rich Internet application accessibility challenges and solutions.
  • ARIA Authoring Practices Guide (APG). The guide was published in this form mid May 2022 to replace the sinlg page working group Note (see below).
  • WAI-ARIA Authoring Practices 1.1: this Working Group Note provides guidance on several aspects of creating accessible rich internet applications: design patterns and widgets, landmark regions, accessible names and descriptions, developing a keyboard interface, grid and table properties, hiding semantics using the presentation role, and role that hide other semantics. (version 1.0 was subtitled “An author's guide to understanding and implementing Accessible Rich Internet Applications”.)
  • ARIA in HTML.
  • HTMLAccessibility API Mappings 1.0: This specification defines how HTML user agents respond to and expose role, state and property information provided for Web content.
  • Core Accessibility API Mappings 1.1: W3C Recommendation 14 December 2017. This document describes how user agents should expose semantics of web content languages to accessibility APIs. This helps users with disabilities to obtain and interact with information using assistive technologies.
  • Core Accessibility API Mappings 1.2 (working draft).
  • WAI-ARIA 1.0 User Agent Implementation Guide: W3C Recommendation 20 March 2014. This older document has been replaced by newer ones that describe API mappings. See WAI-ARIA Overview.
• WAI-ARIA Graphics Module: a specification that is less well known and, as of late 2022, probably not well supported by assistive technologies.
• Personalization Semantics Explainer 1.0 (currently a W3C Working Draft).
• Référentiel Général d'Accessibilité pour les Administrations (RGAA): version 4.1 of the accessibility guidelines for public authorities in France.
  See also Politique de contribution aux logiciels libres de l’État. The guidelines are also available in Markdown format on GitHub: RGAA Référentiel. (An English translation of version 3 is available in the GitHub repository RGAA Guidelines.)
• Guide de l'auditeur RGAA 3 on GitHub.
• United Nations: Accessibility Guidelines for United Nations Websites (last accessed on 15.04.2022).
• New web accessibility guidelines will be ignored, says critic, The Register, 10.10.2007.
  The critic in this article is Joe Clark, who created a competing set of guidelines based on WCAG 1.0 named WCAG Samurai, which has since been taken down. This article has not aged well and is representative of The Register's dismissive stance towards accessibility.

One of the most frequently misunderstood success criteria in WCAG 2.0 and WCAG 2.1 is Success Criterion 4.1.1 Parsing. For a discussion of this criterion and a set of test pages, see Understanding and Testing WCAG 2.1 Success Criterion 4.1.1 on the website Accessibility Works.

Other Accessibility Standards

• CEN: EN 17161:2019: Design for All - Accessibility following a Design for All approach in products, goods and services - Extending the range of users. See also the news item New CEN standard: EN 17161:2019 on Accessibility (no date; accessed on 20.05.2019).
  See also Standard I.S. EN 17161:2019 – Design for All, Centre for Excellence in Universal Design (no date; accessed on 11.05.2022).
• CEN: EN 17210:2021, CEN/CLC/JTC 11 - Accessibility in the built environment (no date; accessed on 11.05.2022).
  See also EN 17210:2021 contributes to an accessible and usable built environment (18.03.2021).
• PAS 78: Guide to good practice in commissioning accessible websites, British Standards Institution (BSI). This standard was published in 2006 in replaced with BS 8878:2010.
• BS 8878:2010: Web accessibility. Code of practice, British Standards Institution (BSI).
  In 2019, this standard was superseded by ISO/IEC 30071-1.
• ISO and IEC: ISO/IEC 30071-1:2019: Information technology — Development of user interface accessibility — Part 1: Code of practice for creating accessible ICT products and services. Below is the standard's abstract:

  This document takes a holistic approach to the accessibility of information and communications technology (ICT) by combining guidance on implementing the accessibility of ICT systems (ICT accessibility) both at organizational and system development levels.

  This document gives guidelines for building and maintaining ICT systems (including products and services) that are accessible to diverse users (including users with disabilities and older people).

  This document is applicable to all types of organizations. This document applies to the breadth of ICT systems and the results of convergent and emerging technologies within an organization including, but not limited to: information systems; intranet systems; websites; mobile and wearable applications; social media; and Internet of Things (IoT) systems.

  It gives requirements and recommendations for organizations:

  1. ensuring accessibility is considered in their policies or strategy by creating an organizational ICT accessibility policy;
  2. embedding the consideration of accessibility decisions through the entire process of developing procuring, installing, operating and maintaining ICT systems, and documenting these choices;
  3. justifying decisions on accessibility;
  4. communicating the ICT system's accessibility decisions to its users at launch, through creating and publishing its accessibility statement.

  
  See also ISO 30071-1 digital accessibility standard – all you need to know (supersedes BS 8878) (Hassell Inclusion, 07.09.2019).
• ISO and IEC: ISO and IEC 29136:2012: Information technology — User interfaces — Accessibility of personal computer hardware. Below is the standard's abstract:

  ISO/IEC 29136:2012 provides requirements and recommendations for the accessibility of personal computer hardware, to be used when planning, developing, designing and distributing these computers. While it does not cover the behaviour of, or requirements for, assistive technologies, it does address connectivity of assistive technologies as an integrated component of interactive systems. Some requirements or recommendations in ISO/IEC 29136:2012 require software support; however, requirements and recommendations that solely focus on software are not included in ISO/IEC 29136:2012.

• ISO and IEC: ISO/IEC 29138-1:2018: Information technology — User interface accessibility — Part 1: User accessibility needs. Below is the standard's abstract:

  This document identifies a collection of user accessibility needs that diverse users have of ICT systems to make these systems accessible to them. Each user accessibility need might be required of a system by an individual. Different users can have different sets of user accessibility needs in different contexts.

  While this set of user accessibility needs was developed for the domain of ICT, many of the user accessibility needs in this set also apply in other domains.

  This document does not provide requirements or specific processes and methods for the application and evaluation of user accessibility needs. However, it could inform the development of such requirements (see 5.4).

  This document is not designed for certification purposes or regulatory or contractual use.

  The user accessibility needs in this document are intended to inform and encourage those responsible for accessibility to go beyond the minimum provisions of accessibility legislation and regulations.

• ISO and IEC: ISO/IEC 13066: Information technology — Interoperability with assistive technology (AT):
  • ISO/IEC 13066-1:2011: Part 1: Requirements and recommendations for interoperability.
  • ISO/IEC TR 13066-2:2016: Part 2: Windows accessibility application programming interface (API).
  • ISO/IEC TR 13066--3:2012: Part 3: IAccessible2 accessibility application programming interface (API).
  • ISO/IEC TR 13066--4:2015: Part 4: Linux/UNIX graphical environments accessibility API.
  • ISO/IEC TR 13066-6:2014: Part 6: Java accessibility application programming interface (API).

Machine-Readable Guideline Representations

Representation of the Web Content Accessibility Guidelines (WCAG) 2.0 in a machine-processable format:

• Karl Groves: WCAG as JSON: represent WCAG 2.1 success criteria (MIT License).
• Vegard Haugstvedt: WCAG as JSON: based on WCAG 2.1 and available under the terms of the MIT licence.
• Wilco Fiers: wcag2json: JSON versions of WCAG 2.0 in various languages, including English, German, Spanish and Dutch. (The repository has no licence.)
• Emerge Interactive: wuhcag-json: YAML files for reach individual WCAG 2.0 success criterion, and a JSON version that combines all this information into a single file. (Licence: Creative Commons Attribution-NonCommercial 4.0 International License.)
• kevee: WCAG 2.0 standard in YAML and JSON format: this repository contains a YAML file containing all the success criteria with their associated techniques and failures, and a JSON file that represents the same data. The repository was last updated in November 2013 and thus represents the September 2013 version of the WCAG techniques, which is now out of date. (See the latest version of Techniques for WCAG 2.0 and the latest version of Techniques for WCAG 2.1.)

Guidelines Focusing on Specific Target Groups or Disabilities

• Aphasia United: Best practice recommendations. These recommendations are available in several languages, including Chinese, Spanish, aphasia-friendly English and aphasia-friendly Japanese.

Office Documents and E-Books

• Accessible Digital Office Document (ADOD) Project: This site has published guidelines for creating accessible documents with various office suites: Microsoft Office (versions 2003 to 2013), LibreOffice and Apache OpenOffice (especially Writer), Google Docs, etcetera. The guidelines also explain how to create accessible templates and how to export documents to “tagged” PDF. For some of these documents, French and Dutch translations are also available.
• IDPF: EPUB Accessibility 1.0: Conformance and Discovery Requirements for EPUB Publications: Recommended Specification 5 January 2017.

Accessibility of Non-Web ICT

• Guidance on Applying WCAG 2.0 to Non-Web Information and Communications Technologies (WCAG2ICT): W3C Working Group Note 5 September 2013.
• IBM Corporation: IBM Accessibility Checklist. Version 7.1 of this checklist was released on 23.06.2019.

Introductions to Accessibility

• Jared Smith: Web Accessibility Fundamentals (YouTube video with subtitles), JavaScript Accessibility Summit 2013.

Contrast / Colour Contrast

• designworkplan: Color contrast (no date).
• Ryan Frederick: In Plain Sight: Text, Contrast, and Accessibility, Medium, June 2016.