Glossary · Accessibility term
WCAG versions (2.0, 2.1, 2.2)
WCAG 2.0 arrived in 2008, WCAG 2.1 in 2018 with rules for mobile, low vision and cognition, and WCAG 2.2 in 2023 with nine more criteria and one removal. The counts confuse people because two different bases are in circulation. WCAG 2.2 has 55 criteria at Levels A and AA, and 86 across all three levels, and both those figures are right. W3C states in the standard itself that content conforming to 2.2 also conforms to 2.1 and 2.0, so building to the newest version answers the older ones, with one reporting wrinkle worth knowing about below. The working group's own advice is to build to 2.2 whatever your obligation names. The obligations lag well behind. Section 508 still names WCAG 2.0, the European standard in force aligns to 2.1, and 2.2 is what a site built today should be measured against.
In practice
Count in one basis at a time or the arithmetic falls apart. WCAG 2.0 published 61 criteria in 2008, 38 of them at Levels A and AA. WCAG 2.1 in 2018 added seventeen, twelve at A and AA, giving 78 in total and 50 at A and AA. WCAG 2.2 in 2023 added nine, six at A and AA, and removed one, giving 86 in total and 55 at A and AA. Anyone adding the headline figures together and landing on 58 has mixed the two bases, which is the most common arithmetic error in this whole subject.
They are backwards compatible, and that is the most useful fact about them. Content conforming to 2.2 also conforms to 2.1 and 2.0, so there is never a reason to aim lower even when your obligation names an older version. There is one reporting asterisk. Because 2.2 removed a criterion, a product tested only against 2.2 has not been tested against that one. A report written against a 2.0 or 2.1 obligation may still need a row for it.
What 2.2 added is usually summarised as focus visibility, target size, dragging and easier logins, which quietly leaves out the two Level A additions. Consistent help and redundant entry are the ones on a minimum-conformance budget, and they are the two most likely to be missing from an older checklist.
The version numbers are not the only citation you will meet. Some national instruments cite an ISO number instead, and only two versions have one. WCAG 2.0 is ISO/IEC 40500:2012 and WCAG 2.2 is ISO/IEC 40500:2025. WCAG 2.1 never got an edition of its own, so a form asking for ISO/IEC 40500 is asking for this standard under another name and the year beside it is the part that says which version.
One more thing that catches people working from an old printout. WCAG 2.2 was republished with errata in December 2024, and that republication changed four normative definitions and reformatted two criteria. A copy dated 2023 is not the current text.
Why it matters
A great many current obligations name 2.1, because regulation lags publication, and testing against 2.2 covers the WCAG half of those without needing to be redone when the rules catch up. It does not answer a law on its own. Levels, non-WCAG requirements and the scope of the report are all still yours to settle, and a product that keeps shipping still needs retesting. That recommendation to build to 2.2 is the working group's own, in writing. WCAG 3.0 is an early draft on a different model, so nothing can be claimed against it yet, which is a different thing from saying do not follow it. W3C has also left the door open to further 2.x releases in the meantime, so treating 2.2 as the end of the line is a guess rather than a fact.
The one your scanner keeps flagging
WCAG 2.2 removed 4.1.1 Parsing, and the current 2.0 and 2.1 texts carry a note treating it as always satisfied for content using HTML or XML. So a checklist that still lists it is not out of date, and for an HTML page nobody should be failed on it. Duplicate IDs are still a real defect, because a label reference and a form association both resolve by ID, and that finding belongs under the rules those break rather than under 4.1.1. One wrinkle for anyone under a regulation. A law that incorporates a dated version freezes the text it names, and the always-satisfied note was added later, so under a dated citation the criterion is still live.
Where this shows up on the site
Related terms
- WCAGWCAG is the international standard for web accessibility, published by the W3C.
- Level A, AA, AAALevel A, AA and AAA are WCAG's three conformance levels, and they stack.
- Success criterionA success criterion is a single testable rule in WCAG, and it is the unit everything else is built from.
- ConformanceConformance means satisfying all the requirements of a standard, and WCAG has five of them rather than one.
Knowing the word is the easy part.
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