WCAG, the Web Content Accessibility Guidelines, is the W3C standard that defines what an accessible website is: a set of testable success criteria, grouped under four principles and sorted into three levels, A, AA and AAA. The current version is WCAG 2.2, and the level almost every law, contract and court settlement asks for is AA. This guide explains WCAG in plain language for site owners, designers and developers: the versions, what each level means, what 2.2 changed, where WCAG 3 stands, and a checklist for level AA. For the wider picture (why accessibility matters, the law and the ten fixes that clear most findings) start with the web accessibility guide.
Quick answer
- WCAG is a W3C standard, not a law. Laws such as the European Accessibility Act and the US ADA Title II rule point to it.
- Target WCAG 2.2 level AA. It is 55 success criteria (31 at A, 24 at AA), and meeting it also meets 2.1 AA.
- Level A removes barriers that stop people completely; AA is the normal legal target; AAA is for specific content, not whole sites.
- WCAG 2.2 (October 2023) added nine criteria, including a 24 × 24 px minimum target size, and removed 4.1.1 Parsing. It is also the ISO standard ISO/IEC 40500:2025.
- WCAG 3 is a working draft. The W3C says it is years from finished and will not replace 2.2 soon; build to 2.2 now.
- Run the free accessibility checker to test the criteria a machine can decide, then test the rest by hand.
What is WCAG?
WCAG is published by the Web Accessibility Initiative (WAI) of the W3C, the body that also standardises HTML and CSS. It describes outcomes, not technologies: "text has enough contrast", not "use this CSS". That is why the same standard applies to a WordPress blog, a React app and a PDF.
Each requirement is a success criterion with a number, a name and a level, for example 1.4.3 Contrast (Minimum), level AA. The number tells you where it sits: principle 1, guideline 1.4, criterion 3. The W3C's "Understanding" page for each criterion explains its intent and how to pass.
The four principles: POUR
Every criterion sits under one of four principles:
| Principle | Question it asks | Examples of criteria |
|---|---|---|
| Perceivable | Can people see or hear the content in some form? | Text alternatives (1.1.1), captions (1.2.2), contrast (1.4.3), reflow at 320 px (1.4.10) |
| Operable | Can people use every control? | Keyboard (2.1.1), no keyboard trap (2.1.2), skip links (2.4.1), visible focus (2.4.7), target size (2.5.8) |
| Understandable | Can people understand the content and the interface? | Page language (3.1.1), labels (3.3.2), error suggestions (3.3.3) |
| Robust | Does it work with assistive technology? | Name, role, value (4.1.2), status messages (4.1.3) |
The principles help when a finding sounds arbitrary. A missing form label is not a style rule; it fails "understandable" and "robust" because a screen reader has nothing to announce.
WCAG versions: 2.0, 2.1, 2.2 and 3
| Version | Published | What changed | Where you meet it |
|---|---|---|---|
| WCAG 2.0 | December 2008 | The modern, testable model | Section 508 (US federal), older contracts |
| WCAG 2.1 | June 2018 | 17 new criteria for mobile, low vision and cognitive needs (reflow, non-text contrast, orientation) | ADA Title II rule, EN 301 549 v3.2.1 |
| WCAG 2.2 | October 2023 | 9 new criteria, 4.1.1 Parsing removed | ISO/IEC 40500:2025, EN 301 549 v4.1.1 |
| WCAG 3 | Working draft | New structure and conformance model | Not for testing yet |
The 2.x versions are backwards compatible: each keeps everything the previous one required (apart from Parsing, which 2.2 dropped as obsolete), so a site that meets 2.2 AA also meets 2.1 AA and 2.0 AA. That is the practical reason to build to 2.2 even when a law names 2.1.
Two standards bodies have caught up with 2.2. In October 2025 ISO approved WCAG 2.2 as ISO/IEC 40500:2025, identical to the W3C text. In September 2026 ETSI published EN 301 549 v4.1.1, the European standard behind the European Accessibility Act, which moves from WCAG 2.1 to WCAG 2.2 for web content. According to the EU's AccessibleEU centre, v3.2.1 (WCAG 2.1) remains the reference for a presumption of conformity until the Commission cites the new version in the Official Journal.
WCAG levels: A, AA and AAA
The levels are cumulative. To conform at AA you meet every A and every AA criterion; AAA adds its criteria on top.
- Level A (31 criteria in 2.2): the barriers that stop people completely. No text alternative for an image, a keyboard trap, content that flashes more than three times a second, a form field with no label.
- Level AA (24 more): what makes a site usable in practice. 4.5:1 text contrast, text that resizes to 200 %, visible focus, consistent navigation, reflow at 320 CSS px, 24 × 24 px targets.
- Level AAA (31 more): stronger versions and specialist needs. 7:1 contrast, sign language for video, a lower reading level, 44 × 44 px targets, no time limits.
WCAG AA vs AAA: which should you aim for?
Aim for AA across the whole site, and use AAA criteria where they fit your audience. The W3C itself advises against requiring AAA as a general policy for entire sites, because some AAA criteria cannot be met for all content: a sign-language version of every video, or a reading level below secondary school for a legal page. Many AAA criteria are still worth adopting selectively. 7:1 contrast for body text, 44 px buttons and link text that makes sense on its own cost little and help a lot.
Conformance: what "meets WCAG 2.2 AA" really means
A conformance claim has rules that are easy to miss. It applies to full pages, not parts of a page, and to complete processes: if the checkout has five steps, all five must conform, because a shopper who cannot pass step three cannot buy. Only accessibility-supported techniques count, meaning ones that work with the browsers and assistive technology people use. There is no official WCAG certificate or badge; a claim is a statement you make and should be able to back with test results, usually in an accessibility statement.
What changed in WCAG 2.2
WCAG 2.2 added nine success criteria and removed one:
| Criterion | Level | In plain language |
|---|---|---|
| 2.4.11 Focus Not Obscured (Minimum) | AA | A focused element is not completely hidden by a sticky header, cookie banner or chat widget |
| 2.4.12 Focus Not Obscured (Enhanced) | AAA | No part of it is hidden |
| 2.4.13 Focus Appearance | AAA | The focus indicator is large and contrasting enough |
| 2.5.7 Dragging Movements | AA | Anything done by dragging (sliders, sortable lists, maps) also works with single clicks or taps |
| 2.5.8 Target Size (Minimum) | AA | Targets are at least 24 × 24 CSS px, or spaced so a 24 px circle around each does not overlap another |
| 3.2.6 Consistent Help | A | Help links, chat or contact details sit in the same place on every page |
| 3.3.7 Redundant Entry | A | Don't ask for the same information twice in one process; prefill or offer "same as billing" |
| 3.3.8 Accessible Authentication (Minimum) | AA | Logging in does not depend on a memory or puzzle test; allow password managers and paste |
| 3.3.9 Accessible Authentication (Enhanced) | AAA | No object or image recognition tests either |
| 4.1.1 Parsing | removed | HTML parsing is now fully specified and assistive technology reads the browser's accessibility tree, not the raw markup, so it no longer protected anyone |
For most sites, three of these create work: sticky headers that cover the focused link (2.4.11), small icon buttons (2.5.8, see the 24 × 24 pixel target-size rule) and login or checkout forms that block paste or repeat questions (3.3.7, 3.3.8).
WCAG 3: the status in September 2026
WCAG 3 (the W3C Accessibility Guidelines) is a working draft; the latest was published on 10 September 2026. The W3C's own introduction says it is not expected to be a completed standard for a few more years, that it will not supersede WCAG 2, and that WCAG 2 will not be deprecated for several years after WCAG 3 is finished. Its advice for preparing is to meet WCAG 2.2 now.
The draft changes the structure. It replaces success criteria with core requirements (all must be met to conform), supplemental requirements and assertions about your process, such as usability testing with disabled people. Levels A, AA and AAA give way to reporting tiers; the working group is still debating these, including a Bronze, Silver and Gold model. None of it is stable enough to test against, and no law references it.
How to check your site against WCAG
About a third of WCAG 2.2 can be decided by a machine from the rendered page. The accessibility checker runs axe-core with the WCAG 2.0, 2.1 and 2.2 A and AA rules, plus getReport's own checks, and names the elements that fail:
The rest needs a person: whether alt text describes the image, whether the focus order makes sense, whether error messages help, whether a video's captions are accurate. The web accessibility guide describes the keyboard pass, the screen reader test and the 200 % zoom check that cover most of it.
A WCAG 2.2 AA checklist
This is a working checklist grouped by what you build, not the full list of 55 criteria. It covers the ones most sites fail; the W3C's "How to Meet WCAG (Quick Reference)" filters the full list by level.
Images and media
- Informative images have alt text; decorative ones have
alt=""(1.1.1). - Videos have captions; audio-only content has a transcript (1.2.1, 1.2.2).
- Sound that autoplays for more than 3 seconds can be paused or muted (1.4.2).
Text and colour
- Text contrast is at least 4.5:1, or 3:1 from 24 px (or about 18.7 px bold) (1.4.3).
- Icons, input borders and focus indicators reach 3:1 against their background (1.4.11).
- Colour is never the only signal: errors and links also have text or underlines (1.4.1).
- Text zooms to 200 % and the page reflows at 320 CSS px without sideways scrolling (1.4.4, 1.4.10).
Structure
- The page has a language (
<html lang="…">) and a unique, descriptive<title>(3.1.1, 2.4.2). - Headings and landmarks reflect the structure; there is a skip link or landmarks to bypass the menu (1.3.1, 2.4.1).
- Link text makes sense in context; no bare "click here" lists (2.4.4).
Keyboard and pointer
- Everything works with the keyboard, with no traps (2.1.1, 2.1.2).
- Focus is visible and never fully hidden under sticky elements (2.4.7, 2.4.11).
- Targets are at least 24 × 24 CSS px or spaced apart (2.5.8); dragging has a click alternative (2.5.7).
Forms
- Every field has a visible label; required fields and formats are stated (3.3.2).
- Errors are described in text, with a suggestion (3.3.1, 3.3.3).
- No repeated questions, and login allows paste and password managers (3.3.7, 3.3.8).
Code
- Custom controls expose name, role and state (4.1.2); status messages such as "Added to cart" are announced (4.1.3).
Common misunderstandings
- "WCAG compliant" as a product feature. A theme or plugin can make conformance easier, but conformance belongs to your pages and content, which you change every week.
- Treating AAA as "better AA". Some AAA criteria do not fit some content at all; aim for AA everywhere.
- Waiting for WCAG 3. It is years away, and 2.2 work carries over.
Questions people ask
What is WCAG?
WCAG (Web Content Accessibility Guidelines) is the international standard for making websites usable by people with disabilities, maintained by the W3C. It is organised under four principles (perceivable, operable, understandable, robust) with testable success criteria at three levels: A, AA and AAA. Most laws and procurement rules, including the European Accessibility Act, point to level AA. An accessibility checker tests the criteria a machine can detect.
What is WCAG 2.2?
WCAG 2.2 is the current version of the Web Content Accessibility Guidelines, published by the W3C in October 2023 and approved as ISO/IEC 40500:2025. It keeps everything in WCAG 2.1, removes the obsolete 4.1.1 Parsing criterion and adds nine success criteria, including a 24 × 24 px minimum target size, focus not hidden behind sticky headers, alternatives to dragging, and logins without memory puzzles. Level AA is the usual legal target.
What is the difference between WCAG 2.1 AA and WCAG 2.2 AA?
WCAG 2.2 AA asks for six more criteria than 2.1 AA and drops one. The additions are focus not obscured, dragging alternatives, 24 px targets, consistent help, redundant entry and accessible authentication; 4.1.1 Parsing is gone. Because 2.2 includes 2.1, a site that meets 2.2 AA also meets 2.1 AA, which is what the ADA Title II rule and older contracts name.
Should I aim for WCAG AA or AAA?
Aim for AA across the whole site. It is the level laws, contracts and courts refer to, and every criterion in it can be met on ordinary content. The W3C advises against requiring AAA for entire sites, because some of it, such as sign language for all video, cannot be met everywhere. Adopt individual AAA criteria where they are cheap, such as 7:1 body-text contrast.
When will WCAG 3 replace WCAG 2.2?
Not for years. WCAG 3 is still a W3C working draft, the latest dated 10 September 2026, and the W3C says it will take a few more years to finish. Even then, WCAG 2 will not be deprecated for several years afterwards, and laws will keep citing 2.1 or 2.2 until they are amended. The W3C's advice is to meet WCAG 2.2 now.
Is WCAG a law?
No. WCAG is a technical standard from the W3C, and it becomes binding only when a law, regulation or contract points to it. Examples are the US ADA Title II rule for state and local governments (WCAG 2.1 AA), the European Accessibility Act through EN 301 549, and Section 508 for US federal agencies. Courts in private ADA lawsuits also use WCAG AA as the yardstick.