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

Perceivable1.4 DistinguishableLevel AAWCAG 2.0

1.4.3: Contrast (Minimum)

Text and images of text have a contrast ratio of at least 4.5:1, except for large text which requires 3:1.

Why this matters

Low contrast text is difficult or impossible to read for users with low vision, color blindness, or when viewing screens in bright sunlight. Approximately 1 in 12 men and 1 in 200 women have color vision deficiency.

Common failures

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

Light gray text on white backgrounds
Placeholder text with insufficient contrast
Disabled button text that's nearly invisible
Brand colors that don't meet contrast ratios
Text overlaid on images without a background
Links that are only distinguished by color with insufficient contrast against surrounding text

How to fix

Use a contrast checker: aim for 4.5:1 for normal text, 3:1 for large text (18px+ or 14px+ bold)
Adjust your color palette — often a slightly darker shade passes while maintaining the brand feel
Add semi-transparent backgrounds behind text overlaid on images
Test in both light and dark mode
Use CSS custom properties to maintain consistent, accessible colors across your site

Related axe-core rules

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

color-contrast

Check your site for 1.4.3 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 1.4.3: Contrast (Minimum) (W3C)