Web Content Accessibility Guidelines (WCAG) 2.1 covers a wide range of recommendations for making Web content more accessible. Following these guidelines will make content accessible to a wider range of people with disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity, and combinations of these. These guidelines address accessibility of web content on desktops, laptops, tablets, and mobile devices. Following these guidelines will also often make your Web content more usable to users in general.
WCAG 2.1 success criteria are written as testable statements that are not technology-specific. Guidance about satisfying the success criteria in specific technologies, as well as general information about interpreting the success criteria, is provided in separate documents. See Web Content Accessibility Guidelines (WCAG) Overview for an introduction and links to WCAG technical and educational material.
WCAG 2.1 extends Web Content Accessibility Guidelines 2.0 [[!WCAG20]], which was published as a W3C Recommendation December 2008. Content that conforms to WCAG 2.1 also conforms to WCAG 2.0, and therefore to policies that reference WCAG 2.0.
Until WCAG 2.1 advances to W3C Recommendation, the current and referenceable document is Web Content Accessibility Guidelines 2.0 [[WCAG20]], published as a W3C Recommendation December 2008.
The introduction to WCAG 2.0 says "even content that conforms at the highest level (AAA) will not be accessible to individuals with all types, degrees, or combinations of disability, particularly in the cognitive, language, and learning areas." While WCAG 2.1 provides additional guidance, it is still true that it does not provide universal coverage. The Working Group plans to add additional clarification about this in the next publication.
To comment, file an issue in the W3C WCAG 2.1 GitHub repository. Although the proposed Success Criteria in this document reference issues tracking discussion, the Working Group requests that public comments be filed as new issues, one issue per discrete comment. It is free to create a GitHub account to file issues. If filing issues in GitHub is not feasible, send email to public-agwg-comments@w3.org (comment archive).
Web Content Accessibility Guidelines (WCAG) 2.1 defines how to make Web content more accessible to people with disabilities. Accessibility involves a wide range of disabilities, including visual, auditory, physical, speech, cognitive, language, learning, and neurological disabilities. Although these guidelines cover a wide range of issues, they are not able to address the needs of people with all types, degrees, and combinations of disability. These guidelines also make Web content more usable by older individuals with changing abilities due to aging and often improve usability for users in general.
WCAG 2.1 is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of providing a shared standard for Web content accessibility that meets the needs of individuals, organizations, and governments internationally. WCAG 2.1 builds on WCAG 2.0 [[!WCAG20]], which in turn built on WCAG 1.0 [[WAI-WEBCONTENT]] and is designed to apply broadly to different Web technologies now and in the future, and to be testable with a combination of automated testing and human evaluation. For an introduction to WCAG, see the Web Content Accessibility Guidelines (WCAG) Overview.
Web accessibility depends not only on accessible content but also on accessible Web browsers and other user agents. Authoring tools also have an important role in Web accessibility. For an overview of how these components of Web development and interaction work together, see:
Further introductory information about the structure of WCAG 2.0, inherited by WCAG 2.1, is available in the introduction to WCAG 2.0. For brevity in this draft it is not repeated here but can be found at:
WCAG 2.1 extends WCAG 2.0 by adding new success criteria, definitions to support them, guidelines to organize the additions, and a couple additions to the conformance section. This additive approach helps to make it clear that sites which conform to WCAG 2.1 also conform to WCAG 2.0, thereby meeting conformance obligations that are specific to WCAG 2.0. The Accessibility Guidelines Working Group recommends that sites adopt WCAG 2.1 as their new conformance target, even if formal obligations mention WCAG 2.0, to provide improved accessibility and to anticipate future policy changes.
The following Success Criteria are new in WCAG 2.1:
Many of these success criteria reference new terms that have also been added to the glossary and form part of the normative requirements of the success criteria.
In the Conformance section, a third note about page variants has been added to Full Pages, and an option for machine-readable metadata added to Optional Components of a Conformance Claim.
In order to avoid confusion for implementers for whom backwards compatibility to WCAG 2.0 is important, new success criteria in WCAG 2.1 have been appended to the end of the set of success criteria within their guideline. This avoids the need to change the section number of success criteria from WCAG 2.0, which would be caused by inserting new success critera between existing success ccriteria in the guideline, but it means success criteria in each guideline are no longer grouped by conformance level. The order of success criteria within each guideline does not imply information about conformance level; only the conformance level indicator (A / AA / AAA) on the success criterion itself indicates this. The WCAG 2.1 Quick Reference provides ways to view success criteria grouped by conformance level, along with many other filter and sort options.
WCAG 2.1 uses the same conformance model as WCAG 2.0 with a couple additions, which is described in the Conformance section. It is intended that sites that conform to WCAG 2.1 also conform to WCAG 2.0, which means they meet the requirements of any policies that reference WCAG 2.0, while also better meeting the needs of users on the current Web.
The Status of This Document section describes how implementation testing of WCAG 2.1 will be performed during the Candidate Recommendation period. In order to advance, the document must meet the exit criteria described. In addition, some features have been marked as "at risk". If a feature does not meet implementation targets by the end of the Candidate Recommendation period, it will be removed. Therefore, the final Web Content Accessibility Guidelines 2.1 could contain fewer requirements than this draft. Implementers are encouraged to pay extra attention to these features to help the Working Group gather implementation experience and avoid the need to remove such features.
In parallel with WCAG 2.1, the Accessibility Guidelines Working Group is working on requirements for a 3.0 version of accessibility guidelines, developed by the Silver Task Force. The result of this work is expected to be a more substantial restructuring of web accessibility guidance than would be realistic for dot-releases of WCAG 2. The task force follows a research-focused, user-centered design methodology to produce the most effective and flexible outcome, including the roles of content authoring, user agent support, and authoring tool support. This is a multi-year effort, so WCAG 2.1 is needed as an interim measure to provide updated web accessibility guidance to reflect changes on the web since the publication of WCAG 2.0.
In order for WCAG 2.1 to achieve its goal to update web accessibility guidance in a time frame that is meaningful before the 3.0 project delivers results, WCAG 2.1 must be completed quickly. This inherently means that some proposed Success Criteria may prove too complex to include in WCAG 2.1, but nonetheless will be viewed as important accessibility guidance for current web content. The larger 3.0 project is expected to incorporate such guidance, but the Working Group could also decide that another set of guidelines between WCAG 2.1 and 3.0 is needed. In that case, a new version, WCAG 2.2, could be proposed. A decision to develop WCAG 2.2 will need to balance the benefits of providing additional accessibility guidance earlier, versus the opportunity cost the work could have on the more substantially restructured and comprehensive 3.0 project. The current Accessibility Guidelines Working Group charter states "The Working Group intends to produce updated guidance for accessibility on a regular interval, starting with WCAG 2.1. Depending on the outcome of the requirements development for the next major update to WCAG, it may be necessary to pursue further dot-releases of WCAG until a major release is ready to be completed in time for a scheduled release date."
Information and user interface components must be presentable to users in ways they can perceive.
Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.
Provide alternatives for time-based media.
Create content that can be presented in different ways (for example simpler layout) without losing information or structure.
Make it easier for users to see and hear content including separating foreground from background.
User interface components and navigation must be operable.
Make all functionality available from a keyboard.
Provide users enough time to read and use content.
Do not design content in a way that is known to cause seizures.
Provide ways to help users navigate, find content, and determine where they are.
New
Make it easier for users to operate pointer functionality.
New
Ensure that device sensor inputs are not a barrier for users.
Information and the operation of user interface must be understandable.
Make text content readable and understandable.
Make Web pages appear and operate in predictable ways.
Help users avoid and correct mistakes.
Content must be robust enough that it can be interpreted by by a wide variety of user agents, including assistive technologies.
Maximize compatibility with current and future user agents, including assistive technologies.
This section lists requirements for conformance to WCAG 2.1. It also gives information about how to make conformance claims, which are optional. Finally, it describes what it means to be accessibility supported, since only accessibility-supported ways of using technologies can be relied upon for conformance. Understanding Conformance includes further explanation of the accessibility-supported concept.
The main content of WCAG 2.1 is normative and defines requirements that impact conformance claims. Introductory material, appendices, sections marked as "non-normative", diagrams, examples, and notes are informative (non-normative). Non-normative material provides advisory information to help interpret the guidelines but does not create requirements that impact a conformance claim.
The key words MAY, MUST, MUST NOT, NOT RECOMMENDED, RECOMMENDED, SHOULD, and SHOULD NOT are to be interpreted as described in [[RFC2119]].
In order for a Web page to conform to WCAG 2.1, all of the following conformance requirements must be satisfied:
One of the following levels of conformance is met in full.
Although conformance can only be achieved at the stated levels, authors are encouraged to report (in their claim) any progress toward meeting success criteria from all levels beyond the achieved level of conformance.
It is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content.
Conformance (and conformance level) is for full Web page(s) only, and cannot be achieved if part of a Web page is excluded.
For the purpose of determining conformance, alternatives to part of a page's content are considered part of the page when the alternatives can be obtained directly from the page, e.g., a long description or an alternative presentation of a video.
Authors of Web pages that cannot conform due to content outside of the author's control may consider a Statement of Partial Conformance.
New A full page includes each variation of the page that is automatically generated by the page for various screen sizes. Each of these variations needs to conform (or needs to have a conforming alternate version) in order for the entire page to conform.
When a Web page is one of a series of Web pages presenting a process (i.e., a sequence of steps that need to be completed in order to accomplish an activity), all Web pages in the process conform at the specified level or better. (Conformance is not possible at a particular level if any page in the process does not conform at that level or better.)
An online store has a series of pages that are used to select and purchase products. All pages in the series from start to finish (checkout) conform in order for any page that is part of the process to conform.
Only accessibility-supported ways of using technologies are relied upon to satisfy the success criteria. Any information or functionality that is provided in a way that is not accessibility supported is also available in a way that is accessibility supported. (See Understanding accessibility support.)
If technologies are used in a way that is not accessibility supported, or if they are used in a non-conforming way, then they do not block the ability of users to access the rest of the page. In addition, the Web page as a whole continues to meet the conformance requirements under each of the following conditions:
In addition, the following success criteria apply to all content on the page, including content that is not otherwise relied upon to meet conformance, because failure to meet them could interfere with any use of the page:
If a page cannot conform (for example, a conformance test page or an example page), it cannot be included in the scope of conformance or in a conformance claim.
For more information, including examples, see Understanding Conformance Requirements.
Conformance is defined only for Web pages. However, a conformance claim may be made to cover one page, a series of pages, or multiple related Web pages.
Conformance claims are not required. Authors can conform to WCAG 2.1 without making a claim. However, if a conformance claim is made, then the conformance claim must include the following information:
A concise description of the Web pages, such as a list of URIs for which the claim is made, including whether subdomains are included in the claim.
The Web pages may be described by list or by an expression that describes all of the URIs included in the claim.
Web-based products that do not have a URI prior to installation on the customer's Web site may have a statement that the product would conform when installed.
If a conformance logo is used, it would constitute a claim and must be accompanied by the required components of a conformance claim listed above.
In addition to the required components of a conformance claim above, consider providing additional information to assist users. Recommended additional information includes:
Refer to Understanding Conformance Claims for more information and example conformance claims.
Refer to Understanding Metadata for more information about the use of metadata in conformance claims.
Sometimes, Web pages are created that will later have additional content added to them. For example, an email program, a blog, an article that allows users to add comments, or applications supporting user-contributed content. Another example would be a page, such as a portal or news site, composed of content aggregated from multiple contributors, or sites that automatically insert content from other sources over time, such as when advertisements are inserted dynamically.
In these cases, it is not possible to know at the time of original posting what the uncontrolled content of the pages will be. It is important to note that the uncontrolled content can affect the accessibility of the controlled content as well. Two options are available:
A determination of conformance can be made based on best knowledge. If a page of this type is monitored and repaired (non-conforming content is removed or brought into conformance) within two business days, then a determination or claim of conformance can be made since, except for errors in externally contributed content which are corrected or removed when encountered, the page conforms. No conformance claim can be made if it is not possible to monitor or correct non-conforming content;
OR
A "statement of partial conformance" may be made that the page does not conform, but could conform if certain parts were removed. The form of that statement would be, "This page does not conform, but would conform to WCAG 2.1 at level X if the following parts from uncontrolled sources were removed." In addition, the following would also be true of uncontrolled content that is described in the statement of partial conformance:
A "statement of partial conformance due to language" may be made when the page does not conform, but would conform if accessibility support existed for (all of) the language(s) used on the page. The form of that statement would be, "This page does not conform, but would conform to WCAG 2.1 at level X if accessibility support existed for the following language(s):"
The full commit history to WCAG 2.1 is available.
Acknowledgements