I've created a document with over 33 obvious priority 1 and priority 2 errors according to WCAG 1.0, and ran them through the leading accessibility validators, and the W3C's markup validation service. None of them successfully found any of the errors, with one of them reporting an error that didn't exist.
Author: Gez Lemon
- Invalid Content
- Cynthia Says Accessibility Validator
- HiSoftware Accessibility Validator
- Site Valet Accessibility Validator
- WebAIM Wave Accessibility Validator
- Watchfire's WebXACT Validator
- W3C Markup Validation Service
Automated accessibility validation tools are really useful for a quick spot check of any obvious mistakes in markup, but it's important to remember that they can only provide a very rough guide, and a positive report does not imply an accessible page. To illustrate this, I've created a document with priority 1 and priority 2 errors (at least 33 obvious errors, many compounded) according to the Web Content Accessibility Guidelines 1.0. I then ran the document through the leading accessibility validators, checking for priority 1, 2, and 3 errors, with interesting results. The document was also run through the W3C's markup validation service.
Cynthia Says Accessibility Validator
Cynthia Says reports no errors, but reports two priority three warnings for creating a logical tab order, and providing keyboard shortcuts. Interestingly, both priority 3 warnings are contentious areas of web accessibility, which are arguably best avoided for true accessibility.
HiSoftware Accessibility Validator
HiSoft has the same interface as Cynthia Says, and reports the same results.
Site Valet Accessibility Validator
Site Valet found no errors or warnings, but displays the default text of,
possible fail - check warnings, when there were no warnings.
WebAIM Wave Accessibility Validator
WebAIM Wave reported no errors, and the only warning was that it found a table with no structural markup, and hoped that it was for layout; it was.
Watchfire's WebXACT Validator
There was a time when Bobby was easily one of the better accessibility validators. Since being taken over from the Center for Applied Special Technology by Watchfire, and turned into WebXACT, the number of false positives reported by the validator make it the worse of the current crop. WebXACT passes the document for priority 1 and priority 2 issues, for which there are plenty of obvious errors, but fails the document at level 3:
select elements, which are neither edit boxes nor text areas.
W3C Markup Validation Service