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WAI: Strategies, guidelines, resources to make the Web accessible to people with disabilities

Overview of WCAG 2.0 Documents

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An acronym for the WCAG 2.0 principles is POUR:

  • Perceivable
  • Operable
  • Understandable
  • Robust

Quick links: How to Meet WCAG 2.0 (Quick Reference), WCAG 2 FAQ, WCAG 2.0

Recent updates: WCAG 2 FAQ, 3 November 2008

Introduction

This page gives you an overview of the Web Content Accessibility Guidelines (WCAG) 2.0 documents, and highlights how WCAG 2.0 working drafts differ from WCAG 1.0. If you want to know what Web content means, who WCAG is for, and who develops WCAG, see the high-level WCAG Overview. See also:

WCAG 1.0 was approved in May 1999 and is the stable and referenceable version. WCAG 2.0 documents are being developed to apply to more advanced Web technologies, be easier to use and understand, and be more precisely testable, as documented in Requirements for WCAG 2.0.

WCAG 2.0 was published as a "W3C Proposed Recommendation" on 3 November 2008, as explained the WCAG 2 FAQ answer to "What is the current status of WCAG 2.0?". The FAQ explains the benefits of using WCAG 2.0 now.

The WCAG 2.0 Documents

Web Content Accessibility Guidelines (WCAG) 2.0 is expected to become a Web standard W3C Recommendation in December 2008. WCAG 2.0 itself is designed as a technical standard. Most people will use the supporting materials when developing Web content and Web tools, instead of the actual technical standards document.

The WCAG 2.0 supporting technical materials include:

Additional information is provided in:

Start with the How to Meet "Quick Reference"

The best place to start working with WCAG 2.0 is currently How to Meet WCAG 2.0 (Quick Reference). It includes the WCAG 2.0 guidelines and success criteria. The success criteria are the testable statements that define how Web content meets (conforms to) WCAG 2.0. Under each success criteria are a list of sufficient techniques; that is, if you implement those techniques you meet the success criteria. It also lists common failures, things that do not meet the guidelines.

You can customize How to Meet WCAG 2.0 based on whether you are using CSS, JavaScript, or other Web technologies. You can also select to show Level A, AA, or AAA success criteria.

Within How to Meet WCAG 2.0 are [Understanding Guideline x] and [Understanding Success Criterion x.x.x] links that take you to the relevant page of Understanding WCAG 2.0 that explains the intent of the guideline or success criterion; provides examples and techniques; and describes how it helps people with different disabilities.

Planned Additions

WAI has been focusing on developing the technical aspects of WCAG 2.0. We are also planning material to help Web developers who are not accessibility experts develop accessible Web content that conforms to WCAG 2.0, such as "Application Notes" (working title) would provide guidance for a specific topic, 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.

Navigating WCAG 2.0 Documents

In early drafts, Techniques for WCAG 2.0 and Understanding WCAG 2.0 were long documents in single Web pages. Since the December 2007 publications, each topic is now in a separate short Web page. You can still get the Techniques for WCAG 2.0 and Understanding WCAG 2.0 with all the information in a single file from the "single HTML file" link in the footer.

Addional guidance on navigating the different WCAG 2.0 documents will be provided in November or December 2008.

How WCAG 2.0 Differs from WCAG 1.0

WCAG 2.0 applies more broadly to different Web technologies and is designed to apply as technologies develop in the future. The WCAG 2.0 requirements are more testable.

In WCAG 1.0, brief descriptions are included in the main WCAG 1.0 document under each guideline. With WCAG 2.0, extensive guidance is provided for each guideline and success criteria in Understanding WCAG 2.0. The WCAG 2.0 techniques are also more comprehensive and include tests.

WCAG 1.0 Priority Checkpoints versus WCAG 2.0 Level Success Criteria

WCAG 1.0 is organized around guidelines that have checkpoints, which are priority 1, 2, or 3. The basis for determining conformance to the WCAG 1.0 are the checkpoints.

WCAG 2.0 is organized around four design principles of Web accessibility. Each principle has guidelines, and each guideline has success criteria at level A, AA, or AAA . The basis for determining conformance to the WCAG 2.0 Working Draft are the success criteria.

In WCAG 2.0, a single issue can be covered by more than one success criteria at difference levels. For example, color contrast is covered by two success criteria:

Changes in Requirements

Comparison of WCAG 1.0 Checkpoints to WCAG 2.0 lists each WCAG 1.0 checkpoint and shows how it relates to WCAG 2.0, and it lists the new requirements in WCAG 2.0. The Comparison document is available in two versions:

Transitioning from WCAG 1.0 to WCAG 2.0

Most Web sites that conform to WCAG 1.0 should not require significant changes in order to conform to WCAG 2.0, and some may not need any changes. To help you transition to WCAG 2.0, WAI is developing:

See the WCAG 2 FAQ answer to "When should I start using WCAG 2.0?" for more information on the benefits of using WCAG 2.0 now.