Most scan tools on the market have updated their rule sets to include Web Content Accessibility Guidelines (WCAG) 2.2 Level AA criteria, but coverage depth varies significantly between products. Because automated scans only flag approximately 25% of accessibility issues, the more relevant question is not whether a scanner references 2.2 AA, but how many of those criteria it can actually evaluate.
| Key Point | What It Means |
|---|---|
| Updated Rule Sets | Most actively maintained scanners have added checks for WCAG 2.2 AA criteria introduced in the June 2023 update. |
| Automated Limitation | Scans detect approximately 25% of accessibility issues regardless of which WCAG version they reference. |
| Criteria Type Matters | Some 2.2 AA criteria require human judgment and cannot be evaluated by any automated scan. |
| Marketing vs. Reality | A scanner claiming “WCAG 2.2 AA coverage” may only check a subset of the criteria it can programmatically evaluate. |
What WCAG 2.2 AA Criteria Can Scans Evaluate?
WCAG 2.2 AA builds on 2.1 AA and is backwards compatible, meaning any criterion from earlier versions still applies. Scanners that covered 2.1 AA already check the inherited criteria. The question is what they do with the criteria specific to 2.2.
Some 2.2 criteria involve visual presentation and interaction patterns that automated tools can partially flag. For example, a scanner might detect whether a focus indicator exists in the code. Whether that indicator is sufficiently visible to a real user, however, requires human evaluation.
Other 2.2 criteria relate to authentication flows and redundant entry, which depend on page context and user behavior. No scan tool can assess whether a site forces users to re-enter information they already provided or whether a cognitive function test is required to log in. These require a broader evaluation strategy that goes beyond automated checks.
How to Evaluate a Scanner’s 2.2 AA Claims
When a scan tool advertises WCAG 2.2 AA support, look at the specifics. The product’s documentation should list exactly which success criteria its rules map to. A rule set that maps to 2.2 AA as a whole without specifying individual criteria is less transparent than one that publishes a criterion-by-criterion breakdown.
Open source scanners often publish their rule-to-criterion mapping in public repositories. Browser-based scanners and API-based scanners may provide this in their documentation or conformance statements. Command-line scanners typically list supported rules in their configuration files.
The number of rules is less important than what those rules actually evaluate. A scanner with 400 rules that each check a narrow code pattern may cover fewer criteria than a scanner with 150 well-designed rules that address broader patterns.
Why Version Coverage Alone Is Not Enough
Selecting a scan tool based solely on its WCAG version label misses the larger picture. Two scanners can both claim 2.2 AA coverage while differing substantially in what they flag and how accurately they flag it.
Scans are one component of an accessibility evaluation, not a substitute for one. An audit conducted by an accessibility professional identifies the remaining 75% of issues that no automated tool can catch. The scanner’s version support determines which coded patterns it checks. The audit determines whether the site actually conforms.
A scan tool that covers WCAG 2.2 AA criteria is a starting point for programmatic checks, not a conformance assessment on its own.