Web Content Accessibility Guidelines

The Web Content Accessibility Guidelines are part of a series published by the Web Accessibility Initiative of the World Wide Web Consortium, the main international standards organization for the Internet. They are a set of recommendations for improving web accessibility, primarily for people with disabilities—but also for all user agents, including highly limited devices, such as mobile phones. WCAG 2.0 was published in December 2008 and became an ISO standard, ISO/IEC 40500:2012 in October 2012. WCAG 2.2 became a W3C Recommendation on 5 October 2023.

History

Earlier guidelines (1995–1998)

The first web accessibility guideline was compiled by Gregg Vanderheiden and released in January 1995, just after the 1994 Second International Conference on the World-Wide Web in Chicago.
Over 38 different Web access guidelines followed from various authors and organizations over the next few years. These were brought together in the Unified Web Site Accessibility Guidelines compiled at the University of Wisconsin–Madison.
Version 8 of the Unified Web Site Accessibility Guidelines, published in 1998, served as the starting point for the W3C's WCAG 1.0.

Version 1 (1999–2000)

The WCAG 1.0 were published and became a W3C recommendation on 5 May 1999. In February 2008, The WCAG Samurai, a group of developers independent of the W3C, and led by Joe Clark, published corrections for, and extensions to, the WCAG 1.0.

Version 2 (2001–present)

The first concept proposal of WCAG 2.0 was published on 25 January 2001. In the following years new versions were published intended to solicit feedback from accessibility experts and members of the disability community. On 27 April 2006 a "Last Call Working Draft" was published. Due to the many amendments that were necessary, WCAG 2.0 was published again as a concept proposal on 17 May 2007, followed by a second "Last Call Working Draft" on 11 December 2007. In April 2008 the guidelines became a "Candidate Recommendation". On 3 November 2008 the guidelines became a "Proposed Recommendation". WCAG 2.0 was published as a W3C Recommendation on 11 December 2008. In October 2012, WCAG 2.0 were accepted by the International Organization for Standardization as an ISO International Standard, ISO/IEC 40500:2012. In early 2014, WCAG 2.0's Level A and Level AA success criteria were incorporated as references in clause 9.2 of the European standard EN 301 549 published by ETSI. EN 301 549 was produced in response to a mandate that the European Commission gave to the three official European Standardisation Organisations and is the first European Standard for ICT products and services.
WCAG 2.2 became a W3C Recommendation on 5 October 2023. Nine new criteria make their definitive debut in this new version of the WCAG standard. New sections have also been introduced that detail aspects of the specification which may impact privacy and security.

Version 3 (under development)

In early 2021, the Accessibility Guidelines Working Group presented the first public working draft of the future WCAG 3.0, intended to provide a range of recommendations for making web content more accessible., the WCAG 3.0 working draft was last updated in September 2025. No part of WCAG 3.0 is an official recommendation at this time. WCAG 3.0 is a draft undergoing significant development efforts, and the expected release date as an official recommendation is not defined.

Versions

Version 1

WCAG 1.0 consist of 14 guidelines—each of which describes a general principle of accessible design. Each guideline covers a basic theme of web accessibility and is associated with one or more checkpoints that describes how to apply that guideline to particular webpage features.

Guideline 1: Provide equivalent alternatives to auditory and visual content
Guideline 2: Do not rely on colour alone
Guideline 3: Use markup and style sheets, and do so properly
Guideline 4: Clarify natural language usage
Guideline 5: Create tables that transform gracefully
Guideline 6: Ensure that pages featuring new technologies transform gracefully
Guideline 7: Ensure user control of time sensitive content changes
Guideline 8: Ensure direct accessibility of embedded user interfaces
Guideline 9: Design for device independence
Guideline 10: User interim solutions
Guideline 11: Use W3C technologies and guidelines
Guideline 12: Provide context and orientation information
Guideline 13: Provide clear navigation mechanisms
Guideline 14: Ensure that documents are clear and simple

Each of the in total 65 WCAG 1.0 checkpoints has an assigned priority level based on the checkpoint's impact on accessibility:

Priority 1: Web developers must satisfy these requirements, otherwise it will be impossible for one or more groups to access the Web content. Conformance to this level is described as A.
Priority 2: Web developers should satisfy these requirements, otherwise some groups will find it difficult to access the Web content. Conformance to this level is described as AA or Double-A.
Priority 3: Web developers may satisfy these requirements to make it easier for some groups to access the Web content. Conformance to this level is described as AAA or ''Triple-A.''
Version 2

WCAG 2.0 consist of twelve guidelines organized under four principles. Each guideline has testable success criteria. The W3C's Techniques for WCAG 2.0 is a list of techniques that help authors meet the guidelines and success criteria. The techniques are periodically updated whereas the principles, guidelines and success criteria are stable and do not change. WCAG 2.0 uses the same three levels of conformance as WCAG 1.0, but has redefined them. The WCAG working group maintains an extensive list of web accessibility techniques and common failure cases for WCAG 2.0.
WCAG 2.1 is backwards-compatible with WCAG 2.0, which it extends with a further 17 success criteria.
WCAG 2.2 is backwards-compatible with WCAG 2.1 extending it a further nine success criteria and with WCAG 2.0 extending it a further 26 success criteria. Additionally, WCAG 2.2 has deprecated and removed the 4.1.1 success criterion.

Principles	Guidelines	Success Criteria	Conformance Level	Revision
1: Perceivable	1.1 Text Alternatives	1.1.1 Non-text Content		2.0
1: Perceivable	1.2 Time-based Media	1.2.1 Audio-only and Video-only		2.0
1: Perceivable	1.2 Time-based Media	1.2.2 Captions		2.0
1: Perceivable	1.2 Time-based Media	1.2.3 Audio Description or Media Alternative		2.0
1: Perceivable	1.2 Time-based Media	1.2.4 Captions		2.0
1: Perceivable	1.2 Time-based Media	1.2.5 Audio Description		2.0
1: Perceivable	1.2 Time-based Media	1.2.6 Sign Language		2.0
1: Perceivable	1.2 Time-based Media	1.2.7 Extended Audio Description		2.0
1: Perceivable	1.2 Time-based Media	1.2.8 Media Alternative		2.0
1: Perceivable	1.2 Time-based Media	1.2.9 Audio-only		2.0
1: Perceivable	1.3 Adaptable	1.3.1 Info and Relationships		2.0
1: Perceivable	1.3 Adaptable	1.3.2 Meaningful Sequence		2.0
1: Perceivable	1.3 Adaptable	1.3.3 Sensory Characteristics		2.0
1: Perceivable	1.3 Adaptable	1.3.4 Orientation		2.1
1: Perceivable	1.3 Adaptable	1.3.5 Identify Input Purpose		2.1
1: Perceivable	1.3 Adaptable	1.3.6 Identify Purpose		2.1
1: Perceivable	1.4 Distinguishable	1.4.1 Use of Color		2.0
1: Perceivable	1.4 Distinguishable	1.4.2 Audio Control		2.0
1: Perceivable	1.4 Distinguishable	1.4.3 Contrast		2.0
1: Perceivable	1.4 Distinguishable	1.4.4 Resize text		2.0
1: Perceivable	1.4 Distinguishable	1.4.5 Images of Text		2.0
1: Perceivable	1.4 Distinguishable	1.4.6 Contrast		2.0
1: Perceivable	1.4 Distinguishable	1.4.7 Low or No Background Audio		2.0
1: Perceivable	1.4 Distinguishable	1.4.8 Visual Presentation		2.0
1: Perceivable	1.4 Distinguishable	1.4.9 Images of Text		2.0
1: Perceivable	1.4 Distinguishable	1.4.10 Reflow		2.1
1: Perceivable	1.4 Distinguishable	1.4.11 Non-Text Contrast		2.1
1: Perceivable	1.4 Distinguishable	1.4.12 Text Spacing		2.1
1: Perceivable	1.4 Distinguishable	1.4.13 Content on Hover or Focus		2.1
2: Operable	2.1 Keyboard Accessible	2.1.1 Keyboard		2.0
2: Operable	2.1 Keyboard Accessible	2.1.2 No Keyboard Trap		2.0
2: Operable	2.1 Keyboard Accessible	2.1.3 Keyboard		2.0
2: Operable	2.1 Keyboard Accessible	2.1.4 Character Key Shortcuts		2.1
2: Operable	2.2 Enough Time	2.2.1 Timing Adjustable		2.0
2: Operable	2.2 Enough Time	2.2.2 Pause, Stop, Hide		2.0
2: Operable	2.2 Enough Time	2.2.3 No Timing		2.0
2: Operable	2.2 Enough Time	2.2.4 Interruptions		2.0
2: Operable	2.2 Enough Time	2.2.5 Re-authenticating		2.0
2: Operable	2.2 Enough Time	2.2.6 Timeouts		2.1
2: Operable	2.3 Seizures	2.3.1 Three Flashes or Below Threshold		2.0
2: Operable	2.3 Seizures	2.3.2 Three Flashes		2.0
2: Operable	2.3 Seizures	2.3.3 Animation from Interactions		2.1
2: Operable	2.4 Navigable	2.4.1 Bypass Blocks		2.0
2: Operable	2.4 Navigable	2.4.2 Page Titled		2.0
2: Operable	2.4 Navigable	2.4.3 Focus Order		2.0
2: Operable	2.4 Navigable	2.4.4 Link Purpose		2.0
2: Operable	2.4 Navigable	2.4.5 Multiple Ways		2.0
2: Operable	2.4 Navigable	2.4.6 Headings and Labels		2.0
2: Operable	2.4 Navigable	2.4.7 Focus Visible		2.0
2: Operable	2.4 Navigable	2.4.8 Location		2.0
2: Operable	2.4 Navigable	2.4.9 Link Purpose		2.0
2: Operable	2.4 Navigable	2.4.10 Section Headings		2.0
2: Operable	2.4 Navigable	2.4.11 Focus Not Obscured		2.2
2: Operable	2.4 Navigable	2.4.12 Focus Not Obscured		2.2
2: Operable	2.4 Navigable	2.4.13 Focus Appearance		2.2
2: Operable	2.5 Input Modalities	2.5.1 Pointer Gestures		2.1
2: Operable	2.5 Input Modalities	2.5.2 Pointer Cancellation		2.1
2: Operable	2.5 Input Modalities	2.5.3 Label in Name		2.1
2: Operable	2.5 Input Modalities	2.5.4 Motion Actuation		2.1
2: Operable	2.5 Input Modalities	2.5.5 Target Size		2.1
2: Operable	2.5 Input Modalities	2.5.6 Concurrent Input Mechanisms		2.1
2: Operable	2.5 Input Modalities	2.5.7 Dragging Movements		2.2
2: Operable	2.5 Input Modalities	2.5.8 Target Size		2.2
3: Understandable	3.1 Readable	3.1.1 Language of Page		2.0
3: Understandable	3.1 Readable	3.1.2 Language of Parts		2.0
3: Understandable	3.1 Readable	3.1.3 Unusual Words		2.0
3: Understandable	3.1 Readable	3.1.4 Abbreviations		2.0
3: Understandable	3.1 Readable	3.1.5 Reading Level		2.0
3: Understandable	3.1 Readable	3.1.6 Pronunciation		2.0
3: Understandable	3.2 Predictable	3.2.1 On Focus		2.0
3: Understandable	3.2 Predictable	3.2.2 On Input		2.0
3: Understandable	3.2 Predictable	3.2.3 Consistent Navigation		2.0
3: Understandable	3.2 Predictable	3.2.4 Consistent Identification		2.0
3: Understandable	3.2 Predictable	3.2.5 Change on Request		2.0
3: Understandable	3.2 Predictable	3.2.6 Consistent Help		2.2
3: Understandable	3.3 Input Assistance	3.3.1 Error Identification		2.0
3: Understandable	3.3 Input Assistance	3.3.2 Labels or Instructions		2.0
3: Understandable	3.3 Input Assistance	3.3.3 Error Suggestion		2.0
3: Understandable	3.3 Input Assistance	3.3.4 Error Prevention		2.0
3: Understandable	3.3 Input Assistance	3.3.5 Help		2.0
3: Understandable	3.3 Input Assistance	3.3.6 Error Prevention		2.0
3: Understandable	3.3 Input Assistance	3.3.7 Redundant Entry		2.2
3: Understandable	3.3 Input Assistance	3.3.8 Accessible Authentication		2.2
3: Understandable	3.3 Input Assistance	3.3.9 Accessible Authentication		2.2
4: Robust	4.1 Compatible
4: Robust	4.1 Compatible			2.0
4: Robust	4.1 Compatible			2.1