What is WCAG?
WCAG — the Web Content Accessibility Guidelines — is the international standard for making websites usable by people with disabilities, published by the W3C. It comes in versions (2.0, 2.1, 2.2) and three levels (A, AA, AAA); Level AA is the one the law and the courts treat as the benchmark.
Versions (W3C): WCAG 2.0 (2008), 2.1 (2018), 2.2 (5 October 2023, the current version). Each builds on the last and stays backward-compatible.
2.0, 2.1, 2.2 — what changed.
Each version adds criteria; none replaces the last.
- WCAG 2.0 (2008) — the original standard, still referenced in older law.
- WCAG 2.1 (2018) — added mobile, low-vision and cognitive criteria. The current legal benchmark.
- WCAG 2.2 (2023) — the latest version, nine further criteria. Backward-compatible with 2.1.
- Backward-compatible — meeting 2.2 means you also meet 2.1 and 2.0.
A, AA, AAA — which you need.
WCAG has three conformance levels. Level A is the minimum, AAA the strictest (and rarely required in full). Level AA is the target almost everyone means by ‘compliant’ — it is what the ADA, US courts, the UK and the EU all point to.
WCAG 2.1 AA, in practice.
For most websites the answer is WCAG 2.1 Level AA. The US Title II rule names it, the EU’s standard is built on it, and courts apply it under the ADA. WCAG 2.2 AA is the forward-looking target as adoption grows.
Common questions.
What is WCAG?
WCAG — the Web Content Accessibility Guidelines — is the international standard, published by the W3C, for making web content usable by people with disabilities. It defines testable criteria across three levels.
What is the difference between WCAG 2.0, 2.1 and 2.2?
Each version adds criteria to the last and stays backward-compatible. 2.0 (2008) is the original, 2.1 (2018) added mobile and cognitive criteria and is the current legal benchmark, and 2.2 (2023) is the latest with nine more.
What does WCAG Level AA mean?
WCAG has three levels: A (minimum), AA, and AAA (strictest). Level AA is the standard meant by ‘compliant’ — the one the ADA, courts, the UK and the EU treat as the benchmark.
Which version of WCAG do I need to meet?
For most websites, WCAG 2.1 Level AA. The US Title II rule names it, the EU’s EN 301 549 is built on it, and courts apply it under the ADA. WCAG 2.2 AA is the forward-looking target.
Is WCAG a law?
No — WCAG is a technical standard, not a law. But laws and courts in the US, UK and EU reference it as the benchmark for what an accessible website must do.
Does meeting WCAG 2.2 mean I meet 2.1?
Yes. The versions are backward-compatible, so a site that conforms to WCAG 2.2 also conforms to 2.1 and 2.0.
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