Accessibility Testing Checklist

ESSAY • JULY 16, 2025 • 1,000 WORDS

This checklist ensures all accessibility and performance improvements are properly tested and verified.

Automated Testing

Lighthouse Scores

Run in Chrome DevTools (F12 → Lighthouse tab)

  • Performance Score: Target 90+
    • First Contentful Paint (FCP) < 1.8s
    • Largest Contentful Paint (LCP) < 2.5s
    • Cumulative Layout Shift (CLS) < 0.1
    • Time to Interactive (TTI) < 3.8s
  • Accessibility Score: Target 95+
  • Best Practices Score: Target 100
  • SEO Score: Target 100

axe DevTools

Install browser extension and run on each page type

  • Homepage: 0 violations
  • Blog post page: 0 violations
  • Research page: 0 violations
  • Writing page: 0 violations
  • Projects page: 0 violations
  • About page: 0 violations

WAVE (WebAIM)

Alternative accessibility testing tool

  • No errors on any page
  • Contrast errors resolved
  • Structural errors resolved

Manual Testing

Keyboard Navigation

Test without using mouse/trackpad

  • Tab through all interactive elements
  • Focus indicators clearly visible
  • Skip links work correctly
  • Modal/menu traps focus appropriately
  • Escape key closes modals/menus

Screen Reader Testing

Use NVDA (Windows) or VoiceOver (Mac)

  • Page structure announced correctly
  • Heading hierarchy makes sense
  • Links have descriptive text
  • Images have appropriate alt text
  • Form labels announced correctly
  • Dynamic content updates announced

Color Contrast Testing

Use browser DevTools or contrast checker

Light Mode

  • Normal text (16px): 4.5:1 ratio minimum
  • Large text (24px+): 3:1 ratio minimum
  • Link text: 4.5:1 ratio minimum
  • Button text: 4.5:1 ratio minimum

Dark Mode

  • Normal text: 4.5:1 ratio minimum
  • Light gray text (improved to hsl(40deg 5% 70%)): 4.5:1 ratio
  • Link text: 4.5:1 ratio minimum
  • Secondary button text: 4.5:1 ratio minimum
  • Code syntax highlighting: Readable contrast

Mobile Testing

Test on actual devices or responsive mode

  • Touch targets at least 44x44px
  • Text readable without zooming
  • No horizontal scrolling
  • Images load lazily below fold
  • Performance on 3G connection

Specific Improvements Verification

Font Loading

  • No invisible text during load (font-display: swap working)
  • Fonts load in correct order
  • No layout shift from font loading

Image Optimization

  • MDX images use lazy loading
  • Images have width/height attributes
  • No layout shift from image loading
  • Alt text present and descriptive

Heading Hierarchy

  • Every page has exactly one h1
  • No skipped heading levels
  • Headings create logical outline
  • Visual appearance unchanged

Structured Data

  • JSON-LD validates in Google’s tool
  • No errors in Search Console
  • Rich snippets preview correctly

Performance Metrics

Core Web Vitals (Field Data)

After deployment, monitor in Google Search Console

  • LCP: Good (< 2.5s) for 75%+ of users
  • FID: Good (< 100ms) for 75%+ of users
  • CLS: Good (< 0.1) for 75%+ of users

Bundle Size

Check after build

  • CSS < 50KB (gzipped)
  • JS < 100KB (gzipped)
  • Font files optimized

Browser Compatibility

Test in multiple browsers

  • Chrome/Edge (latest)
  • Firefox (latest)
  • Safari (latest)
  • Mobile Safari (iOS)
  • Chrome Mobile (Android)

Documentation

  • All changes documented
  • Maintenance guides updated
  • Known issues documented
  • Future improvements noted

Sign-off

  • All automated tests passing
  • Manual testing complete
  • No regressions identified
  • Performance metrics met
  • Ready for deployment