xsbl is an AI-powered web accessibility scanner that checks your website against WCAG 2.2 AA and AAA criteria. It scans your rendered pages in a real browser, identifies violations like missing alt text, contrast failures, broken ARIA, and keyboard traps, and generates specific code fix suggestions for your actual markup.

How is xsbl different from accessibility overlays?

Unlike overlays that inject JavaScript and only detect about 30% of WCAG issues, xsbl scans your actual rendered DOM in a real Chromium browser. It provides real code fixes instead of cosmetic patches, works with screen readers rather than against them, and produces exportable compliance evidence accepted by courts and auditors.

Does xsbl support WCAG 2.2?

Yes. xsbl covers 90+ rules across WCAG 2.2 AA and AAA criteria, including contrast, alt text, ARIA, keyboard navigation, forms, headings, landmarks, and more. Each issue is mapped to the specific WCAG success criterion it violates.

Can xsbl create GitHub pull requests with accessibility fixes?

Yes. Connect your GitHub repository and xsbl can generate pull requests with AI-suggested code fixes for accessibility issues. You can fix individual issues or use bulk fix to address multiple issues in a single PR.

How much does xsbl cost?

xsbl offers a free tier with 1 site and 3 scans per month. Paid plans start at $19/month for Starter, $69/month for Pro with unlimited sites and 100 scans, and $249/month for Agency with white-label reports, VPAT generation, and dedicated support.

All WCAG criteria

Robust4.1 CompatibleLevel AWCAG 2.0

4.1.1: Parsing

In content implemented using markup languages, elements have complete start and end tags, are nested according to their specifications, do not contain duplicate attributes, and IDs are unique.

Why this matters

Invalid HTML can cause assistive technologies to misinterpret page structure. Duplicate IDs break label associations and ARIA relationships. Malformed markup leads to unpredictable behavior across browsers and screen readers.

Common failures

These are the most frequent ways this criterion is violated in real-world websites:

Duplicate id attributes on the same page
Unclosed elements or incorrect nesting
Duplicate attributes on the same element
ARIA attributes referencing non-existent IDs

How to fix

Validate HTML using the W3C validator or axe-core
Ensure all id values are unique within the page
Fix any unclosed tags or incorrect nesting
Verify all aria-labelledby and aria-describedby references point to existing elements

Related axe-core rules

xsbl uses axe-core to automatically detect violations of this criterion. The following rules are checked:

duplicate-id
duplicate-id-active
duplicate-id-aria

Check your site for 4.1.1 violations

xsbl scans your rendered pages in a real browser and finds violations of this criterion automatically.

Scan your site free

Official reference: Understanding WCAG 4.1.1: Parsing (W3C)