Lighthouse Accessibility

Lighthouse accessibility auditing provides accessibility checks as part of Google’s open-source web quality tool. Available in Chrome DevTools and as a CI/CD tool, Lighthouse makes accessibility testing accessible to all developers.

What Is Lighthouse Accessibility

Lighthouse is an automated tool for improving web page quality. It audits performance, accessibility, best practices, SEO, and progressive web app capabilities. The accessibility audit uses axe-core under the hood.

Lighthouse accessibility scoring aggregates individual check results into a 0-100 score. While the score provides a quick overview, the detailed results identifying specific issues provide more actionable information.

Lighthouse accessibility audits run in:

• Chrome DevTools (Lighthouse panel)
• Chrome Extension
• Command line via Node
• CI/CD pipelines
• PageSpeed Insights web service

How Lighthouse Accessibility Works

Chrome DevTools integration makes Lighthouse immediately available. Open DevTools, navigate to the Lighthouse panel, select Accessibility category, and generate a report.

Reports show:

• Overall accessibility score (0-100)
• Passed audits (things working correctly)
• Failed audits (issues to fix)
• Manual checks (items requiring human verification)
• Not applicable audits (checks that do not apply)

Each failed audit includes:

• Description of the issue
• Elements affected
• WCAG criteria reference
• Remediation guidance

Command line usage enables CI/CD integration:

Lighthouse CI integrates with continuous integration platforms, running audits on every commit and comparing against baselines:

PageSpeed Insights provides web-based Lighthouse auditing without local tools, useful for quick checks of deployed pages.

Key Considerations

• Use Lighthouse for quick accessibility overviews
• Do not rely solely on the score; examine individual audits
• Address failed audits by priority
• Complete manual check items through actual manual testing
• Integrate Lighthouse CI for continuous monitoring
• Use alongside dedicated accessibility tools for deeper analysis
• Remember Lighthouse uses axe-core, so capabilities are similar

Common Questions

What accessibility score is acceptable?

A score of 100 means all automated checks pass, not that the page is fully accessible. Pages can score 100 while having significant accessibility issues that require manual verification.

Treat the score as a baseline indicator. Aim for 100 on automated checks, then supplement with manual testing. A score below 90 indicates clear issues needing attention.

How does Lighthouse compare to dedicated accessibility tools?

Lighthouse provides convenient accessibility checking bundled with other web quality metrics. It uses axe-core, so accessibility-specific results are comparable.

Dedicated tools like axe DevTools provide more detailed accessibility analysis, better issue visualization, and specialized accessibility workflows. Use Lighthouse for quick checks and comprehensive tools for deeper analysis.

Should Lighthouse accessibility be part of CI/CD?

Yes, Lighthouse CI can enforce accessibility standards in deployment pipelines. Configuration specifies score thresholds or specific audits that must pass.

For design systems, testing individual components may be more valuable than page-level Lighthouse audits. Component testing with axe-core catches issues before they reach composed pages.

Summary

Lighthouse accessibility provides axe-core-powered accessibility auditing integrated with Chrome DevTools and available for CI/CD integration. The convenience of bundled web quality metrics makes Lighthouse a practical starting point, though comprehensive accessibility testing benefits from dedicated tools and manual verification.