Web Content Accessibility Guidelines (WCAG) Overview
Web Content Accessibility Guidelines (WCAG) is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of proving a single shared standard for web content accessibility that meets the needs of individuals, organizations, and governments internationally.
The WCAG documents explain how to make web content more accessible to people with disabilities. Web "content" generally refers to the information in a web page or web application, including:
- natural information such as text, images, and sounds
- code or markup that defines structure, presentation, etc.
WCAG is primarily intended for:
- Web content developers (page authors, site designers, etc.)
- Web authoring tool developers
- Web accessibility evaluation tool developers
- Others who want or need a standard for web accessibility
Related resources are intended to meet the needs of many different people, including policy makers, managers, researchers, and others.
WCAG is a technical standard, not an introduction to accessibility. For introductory material, see Where should I start? in the FAQ.
WCAG 2.0 is a stable, referenceable technical standard. It has 12 guidelines that are organized under 4 principles: perceivable, operable, understandable, and robust. For each guideline, there are testable success criteria, which are at three levels: A, AA, and AAA.
For a short summary of the WCAG 2.0 guidelines, see WCAG 2.0 at a Glance.
To learn about web accessibility principles and guidelines, see Accessibility Principles.
The WCAG 2.0 supporting technical materials include:
- How to Meet WCAG 2.0: A customizable quick reference to Web Content Accessibility Guidelines 2.0 requirements (success criteria) and techniques is essentially the WCAG 2.0 checklist. Most people use this quick references as the main resource for working with WCAG.
- Techniques for WCAG 2.0 gives you specific details on how to develop accessible Web content, such as HTML code examples. The techniques are "informative", that is, you do not have to use them. The basis for determining conformance to WCAG 2.0 is the success criteria from the WCAG 2.0 standard, not the techniques. Read more in Techniques in the FAQ.
- Understanding WCAG 2.0 has additional guidance on learning and implementing WCAG 2.0 for people who want to understand the guidelines and success criteria more thoroughly.
For more details on how these document are related and how they are linked, see The WCAG 2.0 Documents.
Technical document format
The WCAG, Techniques, and Understanding documents follow the W3C format for technical reports, which has several sections at the beginning, including links to different versions, editors, abstract, and status.
WAI is planning additional material to help web developers develop accessible web content that conforms to WCAG 2.0. In 2012 we plan to develop "Application Notes" (working title) to provide guidance for specific topics, such as images, links, or tables. For example, an Application Note on forms would start with simple examples and include the WCAG 2.0 success criteria, techniques, and strategies for developing accessible forms.
WCAG 2.0 is approved as an ISO standard: ISO/IEC 40500:2012. ISO/IEC 40500 is exactly the same as the original WCAG 2.0, which is introduced above along with supporting resources.
Authorized Translations and unofficial translations of WCAG 2.0 are listed in WCAG 2.0 Translations.
WCAG is part of a series of accessibility guidelines, including the Authoring Tool Accessibility Guidelines (ATAG) and the User Agent Accessibility Guidelines (UAAG). Essential Components of Web Accessibility explains the relationship between the different guidelines.
The WCAG technical documents are developed by the Web Content Accessibility Guidelines Working Group (WCAG WG), which is part of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI).
Opportunities for contributing to WCAG and other WAI work are introduced in Participating in WAI.
See the WCAG 2 FAQ for more information on: