Mercury SkillsMercury Skills
v1.0.0 cosmicstack-labs

Accessibility Testing

WCAG 2.1/2.2 audit, axe, Lighthouse, manual testing, screen reader testing, and remediation

View source0 downloads
accessibilitya11ytestingwcaginclusive

Accessibility Testing#

Systematically test and improve web accessibility.

WCAG Guidelines (Quick Reference)#

LevelConformanceTarget
AMinimumMust pass all A criteria
AAStandardLegal standard (ADA, Section 508)
AAAAdvancedHighest level, not always achievable

Key Success Criteria#

  • 1.1.1 (A): All non-text content has text alternative
  • 1.4.3 (AA): Color contrast ≥ 4.5:1
  • 2.1.1 (A): All functionality via keyboard
  • 2.4.7 (AA): Visible focus indicators
  • 4.1.2 (A): Proper ARIA roles and attributes

Testing Approach#

Automated (Catches ~30%)#

// axe-core in CI
const { axe } = require('jest-axe');
it('should have no accessibility violations', async () => {
  render(<MyComponent />);
  const results = await axe(document.body);
  expect(results).toHaveNoViolations();
});

Manual (Catches ~40%)#

  • Tab through all interactive elements
  • Test with high contrast mode
  • Zoom to 200% — no content should be cut off
  • Disable CSS — content should be in logical order

Assistive Technology (Catches ~30%)#

  • Test with VoiceOver (macOS/iOS)
  • Test with NVDA (Windows)
  • Test with keyboard only (no mouse/trackpad)

Common Fixes#

  • Add alt text to all images (decorative = alt="")
  • Add aria-label to icon-only buttons
  • Ensure forms have associated <label> elements
  • Add skip-to-content link
  • Use proper heading hierarchy (h1 → h2 → h3, never skip)

More in Testing & QA

View all →