FAQ
Answers on scan results, scoring, and the limits of automated checks.
What exactly does a11y Score check?
a11y Score loads the given URL in a real browser and checks the rendered content with axe-core, Deque Systems’ open-source rule engine, against WCAG 2.1 at conformance level AA plus additional best-practice rules.
Does "no violations found" mean the page is fully accessible?
No. Automated tools like axe-core reliably catch only a subset of WCAG criteria — estimates put it around 30–50%. Things like a sensible reading order, the quality of alt text, or logical keyboard behavior can only be reliably judged through manual testing and, ideally, by actual users of assistive technology. A good result here is a solid starting point, not proof of full compliance.
How is the score (A–G) calculated?
Each violation is weighted by severity (critical highest, minor lowest); the number of affected elements and whether it’s a WCAG rule or a best-practice-only rule further adjust the weight. The sum of all deductions produces a 0–100 score, translated into a letter grade from A (excellent) to G (severely limited).
Why WCAG 2.1 level AA and not AAA?
Level AA is the standard most legal requirements reference — in the EU, primarily the European Accessibility Act (EAA), implemented in Germany via the BFSG. Level AAA includes some criteria that are practically very hard to fully satisfy site-wide, which is why it’s rarely mandated as a blanket target.
Does my site meet legal requirements (EAA/BFSG) if the scan shows no violations?
A good scan score is a strong signal, but not legal advice or an official conformance certificate. Legal compliance depends on the whole site (not just the scanned page), on criteria that can’t be checked automatically, and on how the relevant regulation is interpreted. When in doubt, consult a digital accessibility professional.
Why do I sometimes get a "cached" result?
To save server resources, scan results are cached for a limited time. If a URL was scanned recently, you get the stored result back immediately instead of the page being scanned again.
What’s the difference between "violations", "incomplete", and "inapplicable"?
Violations are issues that were definitively confirmed. "Incomplete" means axe-core couldn’t automatically decide whether a rule passes — that needs a manual check. "Inapplicable" means the rule simply doesn’t apply to this page (e.g. a video-related rule on a page with no video).
Why do I have to pass a captcha check before scanning?
Every scan launches a real browser and loads the target page — that costs compute time. The captcha check (which usually solves itself automatically in the background) prevents automated abuse of the service.
What data is stored when I scan a page?
The scanned URL and the scan result (violations found, score, timestamp) are stored to support caching. See the Privacy Policy for details on handling of personal data.