WCAG is a technical standard published by the W3C, a standards body with no enforcement power. The ADA is a US federal civil rights law with courts behind it. WCAG cannot require anything. The ADA can, and does.
They connect because the ADA never says what an accessible website is, so everybody involved reaches for the only credible technical definition available.
| WCAG | ADA | |
|---|---|---|
| What it is | A technical standard | A civil rights law |
| Published by | The W3C | The US Congress, 1990 |
| Covers | Web content, anywhere in the world | US businesses and governments |
| Mentions websites | That is all it does | Never |
| Enforcement | None | Private lawsuits and the DOJ |
| Says what to do | Precisely, in 55 A and AA criteria | Not at all, for private businesses |
How the Gap Gets Filled
Because Title III of the ADA names no technical standard for private businesses, plaintiffs plead WCAG, expert witnesses test against WCAG, and settlements specify WCAG conformance as the remedy. It is become the de facto standard by consensus rather than by regulation.
For government, that changed. The Department of Justice's Title II rule sets WCAG 2.1 Level AA as a formal legal requirement for state and local government. The deadlines are April 2027 for larger entities and April 2028 for smaller ones. There, the standard is named in the regulation.
One phrase in that regulation does more work than the version number, and almost nobody quotes it. The rule asks for the Level A and AA success criteria and conformance requirements. Not the criteria alone. The conformance requirements are the five clauses at the back of WCAG that most people skip: the level you are claiming, whole pages rather than parts of them, every page in a process, only technologies that assistive technology can actually use, and non-interference from everything else on the page. So for a covered public entity, "we pass the 50 checks" is not what the regulation asked for. It asked for those plus the machinery that says what passing means.
The same regulation then tightens one of them. WCAG lets you meet a criterion with a conforming alternate version freely. The rule permits that route only where making the content directly accessible is not possible for technical or legal reasons. A law can adopt the standard and then ask for more, and this one does.
What That Means for You
- "ADA compliant website" is not a defined thing for a private business. The Title II rule names a standard for state and local government, and nothing equivalent names one for everybody else. There is no certification either, and nobody who could issue one, so a vendor selling ADA certification is selling something that does not exist.
- WCAG 2.1 AA is the practical answer for private businesses, because it is what complaints plead and settlements require.
- Testing against WCAG 2.2 covers it, since the versions are backwards compatible. With one asterisk for a covered public entity: 2.2 retired 4.1.1 Parsing and the Title II rule keeps it, so that rule needs checking on top of a 2.2 audit.
- Meeting WCAG is not immunity. It is strong evidence of good faith and a much better position than not having tested, and it is not a legal shield.
The phrase to be careful with
"ADA compliant" implies a pass mark that does not exist for websites. "Tested against WCAG 2.2 Level AA on these pages, on this date" is a claim you can actually support.
The Rest of the World
The same pattern repeats nearly everywhere. Laws point at WCAG rather than writing their own rules. The European Accessibility Act through EN 301 549, the UK Equality Act, Ontario's AODA, France's RGAA, and Section 508 in US federal procurement.
That is the useful conclusion: one technical target satisfies most of the world's accessibility law at once. Our laws section covers 38 of them with the version each names.
One honest limit
Nothing here is legal advice, and we are not lawyers. What we can tell you is what your site does and does not do against WCAG, with evidence attached. What that means for your legal position is a question for somebody qualified to answer it.