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Web Content Accessibility Guidelines (WCAG) Overview

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Web Content Accessibility Guidelines (WCAG) is developed through the W3C process in cooperation with individuals and organizations around the world, with a goal of providing 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:

Who WCAG is for

WCAG is primarily intended for:

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.

What is in the WCAG 2.0 documents

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:

For more details on how these document are related and how they are linked, see The WCAG 2.0 Documents.


Authorized Translations and unofficial translations of WCAG 2.0 are listed in WCAG 2.0 Translations.

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.

Supplemental guidance

Supplement guidance provides additional information on making the web more accessible. It goes beyond what is covered in WCAG 2.0 and 2.1. Links to supplemental guidance will be added to this section in April 2018.

WCAG 2.0 is ISO/IEC 40500

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.

The content of ISO/IEC 40500 is freely available from www.w3.org/TR/WCAG20; it is available for purchase from the ISO catalogue.

Benefits of WCAG 2.0 as an ISO standard are summarized in ISO in the FAQ. More information on W3C and the ISO process is in the W3C PAS FAQ.

WCAG 2.1 and other guidelines

WCAG 2.1 is currently in development and is scheduled to be published as a standard in June 2018. See What about WCAG 2.1? in the WCAG 2 FAQ for more information.

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.

Who develops WCAG

The WCAG technical documents are developed by the Accessibility Guidelines Working Group (AG WG) (formerly WCAG Working Group ), which is part of the World Wide Web Consortium (W3C) Web Accessibility Initiative (WAI).

WAI updates Techniques for WCAG 2.0 and Understanding WCAG 2.0 periodically. We welcome comments and submission of new techniques.

Opportunities for contributing to WCAG and other WAI work are introduced in Participating in WAI.

More Information

See the WCAG 2 FAQ for more information on: