WCAG conformance levels: A, AA and AAA — which one actually applies to you

If you have been asked to "make the site WCAG compliant" and are trying to work out which of A, AA and AAA to put in the brief, the short answer is AA, named together with a WCAG version. The longer answer is worth two minutes, because the reason AA is the answer is not the one most people assume.

The levels are about applicability, not strictness

The common reading is that A, AA and AAA are easy, medium and hard. That is not what they are. The W3C sorts each success criterion by how universally it can be applied:

• Level A — the barrier blocks people outright, and the fix is possible for essentially any content. A video with no captions, an image with no text alternative, a control that cannot be reached from the keyboard.
• Level AA — the barrier is still severe, and the fix remains broadly achievable across content types. Contrast ratios for normal text, visible focus, consistent navigation, meaningful page titles.
• Level AAA — the requirement is valuable, but it cannot be satisfied for every kind of content. Sign language interpretation for all pre-recorded audio, or a reading level below lower secondary education, cannot be met by a legal contract or a medical reference without destroying what the document is.

That last row is the whole reason AAA sits where it does, and it leads directly to the next point.

The W3C itself advises against AAA as a site-wide target

This is not a corner cut by lazy vendors. The WCAG specification states plainly that Level AAA conformance is not recommended as a general policy for entire sites, precisely because it is not possible to satisfy every Level AAA criterion for some content. A policy demanding blanket AAA is therefore a policy that cannot be honestly met, and the predictable result is a conformance claim that quietly excludes the content that could not comply.

The productive version is per-criterion adoption. Several AAA criteria are entirely reasonable for most sites and worth taking deliberately — enhanced contrast of 7:1 for body text, no interruptions, extended timing controls, context-sensitive help. Adopt the ones that fit your audience, write down which ones you adopted, and keep the site-wide claim at AA.

Every law we cover stops at AA

Across the instruments documented on this site the picture is consistent:

• EN 301 549 incorporates WCAG Level A and AA in its chapter 9 — but it is a strictly broader standard, extending the same criteria to non-web documents and software and adding requirements for hardware, two-way communication and support services.
• Section 508 references WCAG Level A and AA and applies them to electronic documents and software as well as web content.
• The European Accessibility Act does not set criteria of its own; conformance runs through EN 301 549, and therefore lands on AA.

So "we are targeting AAA" is never a legal requirement. It may be an internal ambition, and that is a fine thing to have — but it should not be the sentence in a procurement document, because nobody can deliver it as written.

Name the version, not just the level

"Level AA" on its own is ambiguous. The success criteria differ between WCAG 2.0, 2.1 and 2.2: 2.1 added criteria for mobile, low vision and cognitive accessibility, and 2.2 added several more while removing one. An auditor working to 2.0 AA and an auditor working to 2.2 AA are doing measurably different jobs, and only one of those matches what current European law expects.

Write WCAG 2.2 Level AA in the brief. If a legal instrument binds you, name that too, because it is the stronger claim: EN 301 549 conformance implies WCAG AA for web content, while WCAG AA conformance says nothing about your PDFs or your desktop application.

What this means when you choose a supplier

The level you name changes who can serve you, and the gap is visible in the catalogue. Of the 574 agencies listed here, 423 claim work against WCAG 2.2 — close to universal, which makes it a weak filter on its own. But only 162 claim EN 301 549, 79 claim ADA, 72 Section 508 and 62 BITV.

If your obligation is European, "we do WCAG 2.2 AA" is not the same answer as "we work to EN 301 549", and the second group is roughly a third the size of the first. Ask which one they mean before comparing prices — the difference is not marketing, it is scope: documents, software and support channels either are in the engagement or they are not.

A short checklist before you send the brief

1. State the level and version together: WCAG 2.2 Level AA.
2. Name the legal instrument that binds you, if one does.
3. List any AAA criteria you have chosen to adopt, individually.
4. Say which content is in scope beyond the website — PDFs, apps, kiosks.
5. Ask the supplier to confirm they work to the instrument, not only to WCAG.