A vendor’s proposal says they will “bring the site to Level A.” A procurement form asks you to tick A, AA or AAA. An accessibility plugin’s dashboard shows a badge with three letters on it. Those three letters get quoted far more often than anyone explains them.
This post explains WCAG levels A, AA and AAA as they work in practice: what sits at each level, why AA is the usual target, why nobody expects AAA across a whole site, and what “partial conformance” means when part of a page is outside your control. It stays out of the legal side; for that, see how the ADA and WCAG relate.
What the three WCAG levels describe
Every WCAG success criterion is assigned one of three WCAG conformance levels. The level reflects how basic the requirement is, how many people it affects, and how practical it is to meet on any kind of content.
- Level A holds the most basic requirements. Fail one and a visitor may be shut out of a task completely.
- Level AA adds requirements that remove serious, common barriers and that most sites can meet with reasonable effort.
- Level AAA holds the strictest requirements. They help many people but cannot always be met, depending on the content.
The levels stack. There is no such thing as meeting AA without meeting A. A claim of Level AA means every A criterion and every AA criterion passes on the page.
Examples from each level
The letters make more sense with real criteria next to them. These are some of the ones a business site runs into:
| Level | Examples | What failing looks like |
|---|---|---|
| A | 1.1.1 Non-text Content, 1.2.2 Captions (Prerecorded), 2.1.1 Keyboard, 2.1.2 No Keyboard Trap, 4.1.2 Name, Role, Value, 3.3.2 Labels or Instructions | A menu you cannot open without a mouse; a video with no captions; a button a screen reader announces only as “button” |
| AA | 1.4.3 Contrast (Minimum), 1.4.4 Resize Text, 1.4.10 Reflow, 2.4.7 Focus Visible, 2.5.8 Target Size (Minimum), 4.1.3 Status Messages | Gray text that is hard to read; a page that scrolls sideways when zoomed; no visible outline when tabbing |
| AAA | Sign language for prerecorded video, much higher text contrast, extended audio description, reading level requirements | Usually not “failing” in any everyday sense; these go further than most sites aim |
Notice what the table shows. Level A failures tend to block people completely. Level AA failures make things hard, slow or exhausting for large groups, such as people with low vision or those who zoom. Level AAA items are real improvements, but some of them would be impossible for certain kinds of content.
Why AA is the usual target
Of the three WCAG levels, AA is where the W3C, regulators, procurement teams and most auditors meet. It covers the barriers that affect the most people while staying achievable for a normal business site built on a normal theme. When a policy, a contract, a settlement or a public-sector rule cites WCAG, it almost always names Level AA. For example, the Title II rule the DOJ issued in April 2024 for public entities uses WCAG 2.1 Level AA, and Section 508 incorporates WCAG 2.0 AA.
Level A alone is not a meaningful finish line. A site can pass every A criterion and still have unreadable contrast, content that falls apart at 200 percent zoom, and no visible focus. If a provider offers to “get you to Level A” as the end goal, ask why they are stopping before the level everyone else uses.
When people say “AA,” also ask which version. AA under 2.0, 2.1 and 2.2 are different sets of criteria, because each version added some. Our post on what changed from WCAG 2.1 to 2.2 covers the newest differences.
Why AAA everywhere is not expected
The W3C itself says it does not recommend requiring Level AAA as a general policy for entire sites, because some content cannot satisfy all AAA criteria. A few examples show why:
- Sign language for every video. Reasonable for a key explainer video at a deaf services nonprofit. Not realistic for a restaurant’s dozens of short social clips.
- Much higher contrast. Achievable for body text, but it can rule out parts of a brand palette entirely, including for large headings.
- Reading level limits. A medical practice or law office cannot always explain a procedure or a legal duty at the plain reading level AAA asks for without losing accuracy. The AAA approach is to provide a simpler summary, which is helpful, but not always practical for every page.
That does not make AAA irrelevant. Plenty of teams pick out single AAA criteria that suit their audience. A clinic might add simpler summaries on its most visited pages. A store might use the AAA focus appearance guidance as its design rule for focus outlines. A nonprofit serving older adults might push its contrast higher than AA requires. Picking AAA items deliberately is good practice. Promising AAA for the whole site is a red flag.
Level is not the same as severity
This trips up a lot of owners reading their first audit report. The level tells you where a criterion sits in the standard. It does not tell you how bad a particular failure is on your site.
A missing alt attribute on a decorative divider fails 1.1.1, a Level A criterion, but hurts almost nobody. A contrast failure on the checkout button text fails 1.4.3, a Level AA criterion, and might stop a low-vision customer from finishing an order. A good report lists both the level and a separate severity or priority, based on who is affected and on which task. If you are deciding what to fix first, the severity column matters more than the letters.
The level still matters in one sense: if you are claiming AA, everything at A and AA has to be fixed eventually, low severity or not. Severity sets the order of the work; the level sets what is in scope.
What “conformance” and “partial conformance” mean
Under WCAG, conformance applies to full web pages, and to every page in a process such as a checkout or a booking flow. You cannot exclude the part of the page you would rather not deal with. A product page whose own content is perfect but whose embedded reviews widget fails is not an AA page.
WCAG recognizes that site owners do not always control everything on the page. Third-party content such as a map embed, a social feed or a reviews service may be outside your hands. For those cases the standard describes a statement of partial conformance, where you say the page would conform if the third-party parts were removed, and identify those parts. It is an honest way to describe reality. It is not a loophole, and it does not cover a theme or plugin you chose and could replace.
Formal conformance claims are optional. Most small businesses never publish one. What they publish instead is an accessibility statement: which standard and level they are working toward, what they know is not yet fixed, and how people can report a problem. Our guide to writing an accessibility statement covers honest wording for exactly this situation.
How to use the levels when talking to vendors
When you hire someone, or fill in a client’s questionnaire, these questions keep the conversation honest:
- “Which version and which level?” The answer should be specific, such as WCAG 2.2 Level AA. “ADA compliant” is not a level.
- “Which pages and processes?” A level only means something when you know what was tested. Ask for the list of templates and tasks covered.
- “How do you test the criteria a scanner cannot judge?” Many AA criteria can only be judged by someone actually tabbing and listening. A level claimed on the strength of a scan alone cannot be backed up.
- “What is out of your control?” Good providers tell you which third-party pieces they cannot fix and what your options are.
- “How will we keep it there?” A level is a snapshot. New content and plugin updates change it.
If a tool or badge tells you your site “is AAA” after an instant scan, treat that as marketing. No automated check can establish conformance at any level. For the overall route from audit to fixes to ongoing checks, start from our website accessibility hub, and for the AA set in detail, read our walkthrough of the 2.2 AA criteria. Background on where the levels come from is in our overview of the WCAG standard.
Frequently asked questions
Is Level A good enough for a small business website?
Not as a final target. Level A removes the most severe blockers, but it leaves out contrast, zoom and reflow, visible focus and other barriers that affect many visitors. Audits, settlements and public rules generally use Level AA, so a small business is better served by working toward AA, even if it fixes the A items first.
Can a site be AAA in some places and AA in others?
Yes. Conformance is assessed page by page, so some pages can meet AAA criteria while the rest meet AA. More often, teams adopt a few AAA criteria across the whole site, such as stronger focus styling or simpler summaries, while the formal target stays at Level AA.
Does a higher level mean better SEO or fewer complaints?
Not directly. Some accessibility work overlaps with good SEO, such as clear headings and descriptive links, but no level affects rankings by itself. Complaints come from barriers people actually hit, so fixing the issues on your most used pages and tasks matters more than the letters you can claim.
What should I put on a form that asks which WCAG level my site meets?
Only state what has been tested and is true. If an audit found the site meets WCAG 2.2 AA on the tested pages, say so and name the date. If work is in progress, say you are working toward that level and describe known gaps. Never tick a level based on a scanner score alone.
If you want an honest answer to “which level does our site meet today, and what stands in the way of AA,” our WCAG audit for business sites tests every A and AA criterion on your key pages and tasks and reports what it finds.
Next in this series: The POUR Principles of WCAG, With Everyday Examples
