A, AA, AAA — what each level actually means
Minimum barrier removal
The most basic accessibility requirements — content that fails Level A is unusable for many people with disabilities.
The legal & industry benchmark
What the EU Accessibility Act (via EN 301 549), most ADA settlements, and government procurement standards reference in practice. This is what we test against.
The strictest level
Rarely required site-wide, even by regulation, because some AAA criteria are impractical across all content types.
Four checks, because no single one catches everything
axe-core (Deque)
The most widely used open-source accessibility rules engine, run against your live rendered page.
IBM Equal Access
A second, independently-built rule engine — different coverage means more real issues caught.
AI review layer
Judges the gray-zone calls rules can't: is alt text actually meaningful? Does link text make sense out of context?
Design / contrast check
Reviews visual presentation — color contrast ratios, text sizing and related design-level issues.
Automation covers about a third of WCAG — not all of it
Industry estimates put automatable coverage at roughly 30-40% of WCAG success criteria. That's not a knock on the tooling — it's a structural limit. Whether alt text is meaningful, whether reading order makes sense, whether a keyboard-only user can actually complete checkout: these need a human, or a carefully-built AI reviewer, not a rule engine.
That's why Abledly pairs this free scan with a guided manual-review workflow (29 criteria automation can't catch) on paid plans — so you're covering real conformance, not just the easy third.
Frequently asked questions
What's the difference between WCAG A, AA and AAA?
WCAG defines three conformance levels. Level A covers the most basic accessibility barriers. Level AA is the widely-adopted legal and industry benchmark, referenced by the ADA in practice, the EU Accessibility Act via EN 301 549, and most government and enterprise procurement standards. Level AAA is the strictest level and is not typically required site-wide, even by regulation, because some AAA criteria are impractical for certain types of content.
How much of WCAG can automated tools actually check?
Industry estimates put automatable coverage at roughly 30-40% of WCAG success criteria. The rest — things like whether alt text is meaningful, whether reading order makes sense, or whether a keyboard-only user can actually complete a task — require human judgment or a trained AI reviewer.
What four checks does this scanner run?
axe-core (Deque) and IBM Equal Access are two independent rule-based engines that catch different but overlapping sets of violations. An AI review layer judges the gray-zone issues rules can't, such as whether alt text is meaningful. A design/contrast check reviews visual presentation issues like color contrast and text sizing.
Is WCAG 2.2 different from WCAG 2.1?
WCAG 2.2 adds new success criteria on top of WCAG 2.1 AA (for example around focus appearance and drag-and-drop alternatives) and is backward compatible — content conforming to 2.2 also conforms to 2.1. Most current legal references (like the EAA's EN 301 549) point to WCAG 2.1 AA as the baseline, with 2.2 representing current best practice.
Does a clean WCAG scan mean my site is accessible?
A clean automated scan means no machine-detectable violations were found — it's a strong signal, not a guarantee. Full WCAG conformance requires manual review of the criteria automation can't judge. This is not legal advice.
Test any page against WCAG — free
Four checks, one scan, results in under a minute.
Check your site free