Understanding WCAG 2.1

Updated


Abstract

Understanding WCAG 2.1 is a guide to understanding and using Web Content Accessibility Guidelines (WCAG) 2.1 [[WCAG21]]. It is part of a set of documents that support WCAG 2.1. Please note that the contents of this document are informative (they provide guidance), and not normative (they do not set requirements for conforming to WCAG 2.1). See Web Content Accessibility Guidelines (WCAG) Overview for an introduction to WCAG, supporting technical documents, and educational material.

Status of This Document

This is the official version of "Understanding WCAG 2.1", and is referenced by Web Content Accessibility Guidelines 2.1. This resource is maintained as needed to update interpretive guidance and reference techniques to meet the guidelines.

To comment, file an issue in the W3C WCAG 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).

Introduction

Understanding WCAG 2.1 is a guide to understanding and using Web Content Accessibility Guidelines 2.1 [[WCAG21]] Although the normative definition and requirements for WCAG 2.1 can all be found in the WCAG 2.1 document itself, the concepts and provisions may be new to some people. Understanding WCAG 2.1 provides a non-normative extended commentary on each guideline and each Success Criterion to help readers better understand the intent and how the guidelines and Success Criteria work together. It also provides examples of techniques or combinations of techniques that the Working Group has identified as being sufficient to meet each Success Criterion. Links are then provided to write-ups for each of the techniques.

Relationship to Understanding WCAG 2.0

Understanding WCAG 2.0 [[UNDERSTANDING-WCAG20]] is a substantial resource to support Web Content Accessibility Guidelines 2.0 [[WCAG20]]. Understanding WCAG 2.1 is a parallel resource that supports the new success criteria in WCAG 2.1. At this stage, it only includes content related to new features of WCAG 2.0. Future versions may include content relevant to WCAG 2.0, depending on how WCAG 2.1 evolves and what structure is determined to provide optimal support.

Unlike Understanding WCAG 2.0, this document has not been published as a Technical Report. This change reduces the formality of the document and increases the ability of the Accessibility Guidelines Working Group to maintain the content and optimize the structure. The Working Group considers the content to be authoritative. If feedback indicates the need, the document could be published as a Technical Report in the future.

Structure of Understanding WCAG 2.1

This is not an introductory document. It is a detailed technical description of the guidelines and their Success Criteria. See Web Content Accessibility Guidelines (WCAG) Overview for an introduction to WCAG, supporting technical documents, and educational material.

Understanding WCAG 2.1 is organized by guideline. There is an Understanding Guideline X.X section for each guideline. The intent and any advisory techniques that are related to the guideline but not specifically related to any of its Success Criteria are listed there as well.

The Understanding Guidelines X.X section is then followed by a Understanding Success Criterion X.X.X section for each Success Criterion of that guideline. These sections each contain:

Links are provided from each Guideline in WCAG 2.1 directly to each Understanding Guideline X.X in this document. Similarly, there is a link from each Success Criterion in WCAG 2.1 to the Understanding Success Criterion X.X.X section in this document.

Techniques for WCAG 2.1

Techniques specific to WCAG 2.1 are added to the the techniques for WCAG 2.0, it is one set. The Techniques change log lists the new techniques added since WCAG 2.1 was published.

Understanding documents change Log

A list of significantly updated Understanding documents since WCAG 2.1 was published:

  1. : Updated Understanding Non-text contrast, based on the changes from Pull request 550.

For a more detailed view of recent changes to the informative documents see the github updates.

Acknowledgments

Additional information about participation in the Accessibility Guidelines Working Group (AG WG) can be found on the Working Group home page.