WCAG (Web Content Accessibility Guidelines)

What WCAG is

The Web Content Accessibility Guidelines (WCAG) are an international technical standard that explains how to make websites and other web content usable by people with disabilities.¹

WCAG is written by the Accessibility Guidelines Working Group, part of the Web Accessibility Initiative (WAI) at the World Wide Web Consortium (W3C), the main standards body for the web.¹

The W3C describes web accessibility as building sites, tools and technologies so that people with disabilities can use them: perceive, understand, navigate and interact with the web, and contribute to it.²

WCAG 2.2 says it covers a wide range of needs, including blindness and low vision, deafness and hearing loss, limited movement, speech disabilities, photosensitivity, and to some extent learning disabilities and cognitive limitations.³

Many of the rules exist so that pages work with assistive technology: tools such as screen readers that read a page aloud, magnifiers that enlarge it, voice-control software, and switches or keyboards used in place of a mouse. A page that follows WCAG gives those tools the information they need, such as text descriptions of images and labels for form fields.

The current version is WCAG 2.2, first published on October 5, 2023 and updated on December 12, 2024. The W3C recommends using the latest version.¹

WCAG itself is not a law. The W3C describes WCAG 2 as a stable technical standard that others can reference, and governments, companies and contracts point to it when they set accessibility requirements.⁴

The idea behind it goes back to the web’s inventor. On the W3C’s introduction to accessibility, Tim Berners-Lee is quoted as saying, “Access by everyone regardless of disability is an essential aspect.”²

Origins: the Web Accessibility Initiative and WCAG 1.0

The W3C launched the Web Accessibility Initiative on April 7, 1997, announcing it from Cambridge, Massachusetts. In the announcement, Berners-Lee, then the W3C’s Director, said the web had to be usable by anyone regardless of their abilities or disabilities.⁵

The first version of the guidelines, WCAG 1.0, became a W3C Recommendation (the W3C’s term for a finished standard) on May 5, 1999.⁶

Its editors were Wendy Chisholm and Gregg Vanderheiden of the Trace R and D Center at the University of Wisconsin-Madison, and Ian Jacobs of the W3C.⁶

WCAG 1.0 had 14 guidelines and 65 checkpoints. Each checkpoint had a priority: Priority 1 items were things authors must do, Priority 2 things they should do, and Priority 3 things they may do.⁶

The split was 16 Priority 1 checkpoints, 28 Priority 2 and 19 Priority 3, with two checkpoints whose priority depended on the situation.⁶

Conformance came in three levels. “A” meant meeting all Priority 1 checkpoints, “Double-A” meant Priorities 1 and 2, and “Triple-A” meant all three. These names carried over into the A, AA and AAA levels used today.⁶

The W3C now marks WCAG 1.0 as superseded, with a note that a newer specification is recommended for new adoption. The superseded status dates from May 18, 2021.⁶

WCAG 2.0 and the ISO standard

WCAG 2.0 became a W3C Recommendation on December 11, 2008.⁷ Its requirements are success criteria, written as testable statements.⁷

A key design choice was to keep the rules independent of any one technology. WCAG 2.2’s own summary says its success criteria “are written as testable statements that are not technology-specific,” a principle carried over from 2.0.³

In practice, the same criteria apply whether a page is built with HTML, CSS and JavaScript or with some other web technology.

WCAG 2.0 also defined five conformance requirements that still apply, covering the level met, full pages, complete processes, accessibility-supported technology and non-interference. These are explained in the conformance section below.⁷

In October 2012, the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) published WCAG 2.0 as international standard ISO/IEC 40500:2012.⁸

That edition was withdrawn on September 24, 2025 and replaced by ISO/IEC 40500:2025.⁸ The W3C says the 2025 edition matches the October 2023 text of WCAG 2.2, and that the December 2024 update is expected to be published as ISO/IEC 40500:2026 by late 2026.¹

Alongside the standard, the W3C publishes supporting documents such as “Understanding” pages that explain the intent of each success criterion, and “Techniques” that show ways to meet them.⁴

How WCAG 2 is organized

WCAG 2 has four layers: principles, guidelines, success criteria and conformance levels.¹

At the top are four principles, often remembered by the acronym POUR: content must be Perceivable, Operable, Understandable and Robust.¹

Under the principles sit 13 guidelines in WCAG 2.2. Guidelines are goals, not tests.¹

The tests are the success criteria. Each one has a number, a short name and a level: A, AA or AAA.¹

Some examples from WCAG 2.2 show the range. Success criterion 1.1.1 Non-text Content (Level A) covers text alternatives, such as alt text that describes an image to someone using a screen reader, a program that reads the page aloud.³

Criterion 1.2.2 Captions (Prerecorded), also Level A, requires captions for recorded audio in video. Criterion 2.1.1 Keyboard (Level A) requires that everything can be done with a keyboard alone, which matters to people who cannot use a mouse.³

Criterion 1.4.3 Contrast (Minimum), at Level AA, requires a contrast ratio of at least 4.5:1 between normal text and its background, and at least 3:1 for large text.¹⁰

Criterion 1.4.4 Resize Text (Level AA) deals with text that people enlarge, and 2.4.7 Focus Visible (Level AA) requires that keyboard users can see which element is currently selected.³

A contrast ratio compares the brightness of two colors. Ratios range from 1:1, for two identical colors, to 21:1, for black on white.¹⁰ WCAG treats text of at least 18 point, or 14 point bold, as large text.¹⁰ Light gray text on a white background is a common way to fail the test.

WCAG 2.1 and 2.2

WCAG 2.1 was published on June 5, 2018 and has since been updated, most recently on May 6, 2025.¹¹¹ It added 17 success criteria aimed at three areas: mobile accessibility, people with low vision, and people with cognitive and learning disabilities.¹²

Among the 2.1 additions, 1.3.4 Orientation (AA) says content should not lock users into a single screen orientation, such as upright or sideways, unless that is essential. 1.4.10 Reflow (AA) says content should work at a width of 320 CSS pixels without scrolling in two directions.¹²

A CSS pixel is the unit web designers use for layout. It is not the same as a physical dot on the screen, so a phone with a very sharp display still measures its width in CSS pixels.

WCAG 2.1 also added 1.4.11 Non-text Contrast (AA), which asks for a 3:1 contrast ratio for the visible parts of buttons, form fields and meaningful graphics, and 2.5.3 Label in Name (A), which helps people who control a computer by voice say a button’s visible label to activate it.¹²

WCAG 2.2 was published on October 5, 2023 and updated on December 12, 2024.¹ It added 9 success criteria.¹³

Several of the new criteria deal with everyday frustrations. Focus Not Obscured (Minimum) means a sticky header or cookie banner must not completely hide the item a keyboard user has moved to. Dragging Movements means anything done by dragging, such as reordering a list, must also work with single clicks or taps.¹³

Three criteria are aimed mainly at people with cognitive disabilities. Consistent Help asks that a help option, such as contact details or a chat button, appear in the same relative order on every page where it is offered. Redundant Entry says a process should not make people type the same information twice in the same process.¹³

Accessible Authentication (Minimum) says a login step should not depend on a memory or puzzle task, such as recalling a password or solving a puzzle, unless there is an alternative or help. Allowing password managers and copy-and-paste is one way to meet it.¹³

Target Size (Minimum) is one of the most visible changes for designers: clickable targets should be at least 24 by 24 CSS pixels, with listed exceptions.¹⁴

WCAG 2.2 also removed one criterion. 4.1.1 Parsing, which dealt with errors in HTML code, is described by the W3C as obsolete and removed from WCAG 2.2. The other criteria from 2.0 and 2.1 carried over essentially unchanged.¹³

The versions are designed to be backward compatible. Content that meets WCAG 2.2 also meets WCAG 2.1 and 2.0 at the same level, and WCAG 2.2 does not deprecate WCAG 2.1.¹

What conformance means

In WCAG, conformance means meeting the success criteria at a chosen level. Level A is the minimum. Level AA means a page meets every Level A and Level AA criterion. Level AAA means it meets every criterion at all three levels.¹⁵

Laws and policies usually name Level AA. The U.S. Department of Justice’s 2024 rule for state and local governments uses WCAG 2.1 Level AA, and the federal Section 508 standards use WCAG 2.0 Levels A and AA.¹⁶¹⁷ WordPress expects code in its own core software and official plugins to meet WCAG 2.2 Level AA.¹⁸

The W3C itself advises against demanding the top level everywhere: “It is not recommended that Level AAA conformance be required as a general policy for entire sites.”⁷ The reason given is that some content cannot meet every AAA criterion.⁷

Conformance has five requirements beyond the success criteria themselves:¹⁵

• Conformance level. One level is met in full.¹⁵
• Full pages. Conformance applies to whole web pages; a page cannot conform if part of it is left out.¹⁵
• Complete processes. When a task spans several pages, such as a checkout or sign-up, every page in the process must conform.¹⁵
• Accessibility-supported technology. Only ways of using technology that work with assistive technology can be relied on to meet the criteria.¹⁵
• Non-interference. Parts of a page that do not conform must not block people from using the rest of it.¹⁵

The complete-processes rule has a practical effect: an accessible product page does not help if the payment step that follows cannot be used with a keyboard.

How laws use WCAG

This section is general information, not legal advice. Which rules apply to a particular organization depends on where it operates, who it serves and what it sells.

United States

Under the Americans with Disabilities Act (ADA), the Department of Justice has set a specific web standard only for government. In April 2024 the Department of Justice set WCAG 2.1 Level AA as the technical standard for the web content and mobile apps of state and local governments under Title II of the ADA. The final rule was published in the Federal Register on April 24, 2024.¹⁶

The Title II rule covers state and local governments, including their agencies, special purpose districts, Amtrak and commuter authorities. Governments must also make sure contractors that provide services for them meet it.¹⁶

The rule lists exceptions, for example for archived content kept only for reference, office documents and PDFs posted before the compliance date that are no longer used to access services, content posted by members of the public, and social media posts made before the compliance date. Even then, governments must still communicate effectively with people with disabilities.¹⁶

The rule also limits shortcuts. A government generally should not keep an inaccessible page and offer a separate accessible copy, except where a technical or legal limit makes the main page impossible to fix. It may use other approaches than WCAG 2.1 Level AA only if it can prove they give the same or better accessibility and usability.¹⁶

An interim final rule published on April 20, 2026 pushed the compliance dates back. Governments serving 50,000 or more people moved from April 24, 2026 to April 26, 2027, and smaller governments and special districts moved from April 26, 2027 to April 26, 2028.¹⁹

Businesses open to the public fall under Title III of the ADA instead. In March 2022 guidance, the Department of Justice said businesses must give people with disabilities equal access to what they offer online, and that they have flexibility in how they do it.²⁰

The same guidance said the department did not have a regulation setting out detailed web standards, and pointed to WCAG and the Section 508 standards as helpful guidance.²⁰

Much of the pressure on private businesses comes from lawsuits. The law firm Seyfarth Shaw counted 3,117 website accessibility lawsuits filed in U.S. federal courts in 2025, up from 2,452 in 2024. Its counts leave out cases filed in state courts.²¹

A parallel rule covers organizations that receive federal health funding. Under Section 504 of the Rehabilitation Act, the Department of Health and Human Services requires recipients of its financial assistance to make their web content and mobile apps meet WCAG 2.1 Level AA.²²

An HHS interim final rule published on May 11, 2026 moved those deadlines to May 11, 2027 for recipients with 15 or more employees, and to May 10, 2028 for smaller recipients.²²

Section 508 of the Rehabilitation Act requires access to information and communication technology that federal agencies develop, buy, maintain or use.¹⁷

The U.S. Access Board issued the updated (“refreshed”) Section 508 rule on January 18, 2017. It requires electronic content to conform to WCAG 2.0 Level A and Level AA success criteria and conformance requirements.¹⁷

European Union

The EU’s Web Accessibility Directive (Directive (EU) 2016/2102) obliges public sector bodies to make their websites and mobile apps accessible; it came into full effect in June 2021.²³

The harmonised standard for that directive is EN 301 549, a European standard for the accessibility of information and communication technology produced jointly by the standards bodies CEN, CENELEC and ETSI. Its Annex A explains how to use it to show compliance.²⁴

The version in force, EN 301 549 V3.2.1, was published in March 2021 and harmonised in August 2021. The European Commission says it draws heavily on WCAG 2.1 but also includes requirements that are not part of WCAG 2.1.²³

The Commission adds that meeting every WCAG 2.1 success criterion therefore does not by itself give a presumption of conformity with the directive, and that WCAG 2.2 is not yet referenced in a harmonised version of the standard.²³

The European Accessibility Act (Directive (EU) 2019/882) was adopted on April 17, 2019. Member states had to adopt their national rules by June 28, 2022 and apply them from June 28, 2025.²⁵

The Act reaches into the private sector. Its list of covered services provided to consumers after June 28, 2025 includes e-commerce services, while microenterprises that provide services are exempt from the accessibility requirements.²⁵

ETSI says EN 301 549 is being revised to support the European Accessibility Act.²⁴ Version 4.1.1, which moves the web baseline from WCAG 2.1 to WCAG 2.2, was published on September 2, 2026; until the European Commission cites it in the Official Journal of the EU, V3.2.1 remains the version in force.²⁶

How common accessibility failures are

WebAIM, a non-profit service center at Utah State University, runs automated tests on the home pages of the top 1,000,000 websites and publishes the results as the WebAIM Million.²⁷²⁸ The 2026 report used data collected in February 2026.²⁸

WebAIM found detectable WCAG 2 failures on 95.9% of those home pages, up from 94.8% in 2025. The pages averaged 56.1 detected errors each, and the scan found 56,114,377 errors in total.²⁸

Six kinds of problem made up 96% of all the errors detected:²⁸

The top two map directly to success criteria described above: low contrast fails 1.4.3 Contrast (Minimum), and missing alt text fails 1.1.1 Non-text Content.¹⁰³

An empty link or button is one with no text a screen reader can announce, such as an icon with no label. A missing document language means the page does not tell assistive technology which language to read it in.

WordPress was the most common CMS in the sample, with 252,302 home pages. Those pages averaged 52.8 errors, 5.8% fewer than the overall average. The report found that most pages built on a common CMS had fewer errors than average.²⁸

WebAIM stresses the limits of these numbers. Not all conformance failures can be found automatically, and the absence of detected errors “does not indicate that a page is accessible or conformant.”²⁸

WCAG 3: what comes next

The W3C is developing a successor, WCAG 3, which was known during early work as “Silver.”¹ The latest Working Draft is dated September 10, 2026.²⁹

The W3C calls WCAG 3 an incomplete draft that will change, and says it is not expected to be a completed standard for a few more years.³⁰

WCAG 3 will not replace WCAG 2 right away. The W3C says WCAG 3 “will not supersede WCAG 2,” and that WCAG 2 will not be deprecated for several years after WCAG 3 is finished.³⁰

The September 2026 drafts change how conformance works. In them, content would conform to WCAG 3 by meeting all of its core requirements, with reporting tiers above that point that are still being worked out.³⁰

The drafts also tag requirements by the kind of harm a failure causes, from physical harm and risk to barriers and friction, and the W3C notes that the final requirements will differ from the current draft.³⁰

Until WCAG 3 is final and laws adopt it, the rules described above continue to point to WCAG 2.0, 2.1 or 2.2.¹⁶¹⁷²³

Timeline

1. September 10, 2026W3C publishes an updated WCAG 3 Working Draft²⁹
2. September 2, 2026EN 301 549 V4.1.1, based on WCAG 2.2, published (not yet cited in the Official Journal)²⁶
3. April 20, 2026DOJ interim final rule moves ADA Title II web deadlines to 2027 and 2028¹⁹
4. February 2026WebAIM Million finds detectable WCAG failures on 95.9% of top home pages²⁸
5. September 24, 2025ISO/IEC 40500:2012 withdrawn and replaced by ISO/IEC 40500:2025 (WCAG 2.2)⁸
6. June 28, 2025European Accessibility Act rules start to apply²⁵
7. December 12, 2024Updated WCAG 2.2 Recommendation published³
8. April 24, 2024DOJ ADA Title II rule adopting WCAG 2.1 AA published¹⁶
9. October 5, 2023WCAG 2.2 published with 9 new success criteria¹³
10. March 18, 2022DOJ issues guidance on web accessibility and the ADA²⁰
11. August 2021EN 301 549 V3.2.1, based on WCAG 2.1, harmonised in the EU²³
12. April 17, 2019European Accessibility Act adopted²⁵
13. June 5, 2018WCAG 2.1 published with 17 new success criteria¹²
14. January 18, 2017Refreshed Section 508 standards adopt WCAG 2.0 Level AA¹⁷
15. October 12, 2012WCAG 2.0 published as ISO/IEC 40500:2012⁸
16. December 11, 2008WCAG 2.0 becomes a W3C Recommendation⁷
17. May 5, 1999WCAG 1.0 becomes a W3C Recommendation⁶
18. April 7, 1997W3C launches the Web Accessibility Initiative⁵

What it means for your website

See also

• Americans with Disabilities Act and websites (coming soon)
• Section 508 (coming soon)
• European Accessibility Act (coming soon)
• World Wide Web Consortium (W3C) (coming soon)
• HTML
• Web accessibility
• Website legal requirements for US small businesses (2026)

References

1. WCAG 2 Overview. W3C Web Accessibility Initiative (WAI). 2026-09-17. accessed October 22, 2026.
2. Introduction to Web Accessibility. W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
3. Web Content Accessibility Guidelines (WCAG) 2.2, W3C Recommendation. World Wide Web Consortium (W3C). 2024-12-12. accessed October 22, 2026.
4. WCAG 2 Documents. W3C Web Accessibility Initiative (WAI). 2026-05-05. accessed October 22, 2026.
5. World Wide Web Consortium (W3C) Launches International Web Accessibility Initiative. World Wide Web Consortium (W3C). 1997-04-07. accessed October 22, 2026.
6. Web Content Accessibility Guidelines 1.0, W3C Recommendation. World Wide Web Consortium (W3C). 1999-05-05. accessed October 22, 2026.
7. Web Content Accessibility Guidelines (WCAG) 2.0, W3C Recommendation. World Wide Web Consortium (W3C). 2008-12-11. accessed October 22, 2026.
8. ISO/IEC 40500:2012, Information technology: W3C Web Content Accessibility Guidelines (WCAG) 2.0. International Organization for Standardization (ISO). 2012-10-12. accessed October 22, 2026.
9. WCAG 2 at a Glance. W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
10. Understanding Success Criterion 1.4.3: Contrast (Minimum). W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
11. Web Content Accessibility Guidelines (WCAG) 2.1, W3C Recommendation. World Wide Web Consortium (W3C). 2025-05-06. accessed October 22, 2026.
12. What's New in WCAG 2.1. W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
13. What's New in WCAG 2.2. W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
14. Understanding Success Criterion 2.5.8: Target Size (Minimum). W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
15. Understanding Conformance. W3C Web Accessibility Initiative (WAI). accessed October 22, 2026.
16. Fact Sheet: New Rule on the Accessibility of Web Content and Mobile Apps Provided by State and Local Governments. U.S. Department of Justice, Civil Rights Division (ADA.gov). 2024-04-08. accessed October 22, 2026.
17. Information and Communication Technology (Section 508 Standards and Section 255 Guidelines). U.S. Access Board. accessed October 22, 2026.
18. Accessibility Coding Standards. WordPress Developer Resources. accessed October 22, 2026.
19. Extension of Compliance Dates for Nondiscrimination on the Basis of Disability; Accessibility of Web Information and Services of State and Local Government Entities (91 FR 20902). Federal Register (U.S. Department of Justice). 2026-04-20. accessed October 22, 2026.
20. Guidance on Web Accessibility and the ADA. U.S. Department of Justice, Civil Rights Division (ADA.gov). 2022-03-18. accessed October 22, 2026.
21. Federal Court Website Accessibility Lawsuit Filings Bounce Back in 2025. Seyfarth Shaw LLP, ADA Title III News and Insights. 2026-03-25. accessed October 22, 2026.
22. Extension of Compliance Dates for Nondiscrimination on the Basis of Disability; Accessibility of Web Content and Mobile Applications of Recipients of Departmental Financial Assistance (interim final rule). U.S. Department of Health and Human Services, Office for Civil Rights (Federal Register public inspection). 2026-05-11. accessed October 22, 2026.
23. Web Accessibility Directive: Standards and harmonisation. European Commission. accessed October 22, 2026.
24. EN 301 549 V3: the harmonized European Standard for ICT Accessibility. ETSI. accessed October 22, 2026.
25. Directive (EU) 2019/882 on the accessibility requirements for products and services. EUR-Lex, Publications Office of the European Union. 2019-04-17. accessed October 22, 2026.
26. Updated EN 301 549 Standard Strengthens Accessibility Requirements for ICT Products and Services. National Disability Authority (Ireland). 2026-09. accessed October 22, 2026.
27. About WebAIM. WebAIM. accessed October 22, 2026.
28. The WebAIM Million: The 2026 report on the accessibility of the top 1,000,000 home pages. WebAIM, Utah State University. 2026. accessed October 22, 2026.
29. W3C Accessibility Guidelines (WCAG) 3.0, W3C Working Draft. World Wide Web Consortium (W3C). 2026-09-10. accessed October 22, 2026.
30. WCAG 3 Introduction. W3C Web Accessibility Initiative (WAI). 2026-09-25. accessed October 22, 2026.

Web Building Encyclopedia. First published October 22, 2026. Last reviewed October 22, 2026. Every fact on this page is linked to a source we opened. Spotted an error? Write to [email protected].