Why Does Testing Matter More Than Reading About Accessibility?
Reading WCAG guidelines tells you what to aim for — but only testing tells you what's actually broken. 95% of homepages have detectable accessibility failures (WebAIM Million 2025). Automated tools catch 30–57% of issues. The rest needs manual checks.
If you followed last week's WCAG 2.2 quick wins guide, you already understand the standards. But understanding and doing are different things. The gap between "I know what WCAG 2.2 AA requires" and "my site actually meets it" is where most small businesses get stuck.
Here's the uncomfortable truth: you can read every accessibility guide on the internet and still have a site that locks out disabled visitors. The only way to know where you stand is to test — and then fix what you find.
This guide walks you through exactly that. Which tools to use, how to test manually, what to fix first, and how to build accessibility into your日常工作 so it's not a one-off panic.
What Are the Best Free Accessibility Testing Tools?
The three best free tools are WAVE (visual overlay, great for beginners), axe DevTools (zero false positives, developer-friendly), and Google Lighthouse (built into Chrome, combines accessibility with performance and SEO).
WAVE — Best for Learning
WAVE, made by WebAIM, is the most beginner-friendly accessibility scanner. Install the Chrome or Firefox extension, visit any page on your site, and click the WAVE icon. It overlays coloured icons directly on your page showing exactly where problems are.
- Green tick = passed check
- Red error = serious problem
- Yellow alert = needs human judgement
- Blue feature = structural element detected
Limitation: WAVE scans one page at a time. For a full site audit, visit every page individually — or pay for the WAVE API / Pope Tech for site-wide scanning.
axe DevTools — Best for Accuracy
axe DevTools, built by Deque, runs inside Chrome or Edge DevTools. Open DevTools (F12), find the axe tab, and click "Scan." It reports issues with the exact HTML line, the WCAG criterion affected, and a fix suggestion.
The key selling point: zero false positives by design. If axe reports an issue, it's genuinely an issue. WAVE and Lighthouse sometimes flag things that need human judgement — axe doesn't.
- Free tier: Individual use, unlimited scans
- Pro tier (~£45/user/month): Guided testing, CI/CD integration
- Engine: axe-core — downloaded over 4 billion times (Deque, 2026)
Google Lighthouse — Best for a Quick Baseline
Lighthouse is built into Chrome DevTools. Open DevTools → Lighthouse tab → tick "Accessibility" → Generate report. It scores your page out of 100 and lists issues with affected elements.
Limitation: Lighthouse uses axe-core for its accessibility checks, but only a subset. It catches roughly 52% of WCAG violations — less than running axe directly. Use it as a starting point, not the final word.
Free Accessibility Tools Compared
| Feature | WAVE | axe DevTools | Lighthouse | Pa11y |
|---|---|---|---|---|
| Developer | WebAIM | Deque | Open source | |
| Type | Browser extension | Ext. + CLI | Chrome DevTools | CLI tool |
| WCAG 2.2 | Yes | Yes | Partial | Yes |
| Visual overlay | Best-in-class | DevTools panel | None | None |
| CI/CD | Paid only | Yes | Yes | Yes (free) |
| Price | Free | Free / £45 Pro | Free | Free |
Our recommendation: Run all three. Start with WAVE to understand your issues visually, use axe for accurate developer-focused reporting, and Lighthouse for a quick baseline score.
Which Specialist Tools Are Worth Knowing About?
Beyond the big three, Pa11y (free CLI tool) is excellent for automated testing in CI/CD pipelines. Accessibility Insights (Microsoft) provides guided manual testing workflows.
Pa11y — Free, Open Source, CI/CD Ready
Pa11y is a command-line tool that runs axe-core or HTML_CodeSniffer against your pages. Install with npm install -g pa11y, then run pa11y https://yoursite.co.uk for an instant report.
The real power is pa11y-ci — run it in your GitHub Actions or GitLab CI pipeline and it fails your build if accessibility drops below a threshold.
Accessibility Insights (Microsoft)
Accessibility Insights is a free browser extension that provides a guided manual testing workflow. It walks you through keyboard testing, tab order verification, and visual checks step by step.
How Do You Manually Test for Accessibility Issues?
Automated tools catch 30–57% of WCAG issues. The rest requires manual testing. A manual pass on a small business site (5–15 pages) takes 2–4 hours.
Step 1: Keyboard-Only Navigation
Unplug your mouse. Seriously. Now Tab through every page on your site.
- Can you reach every interactive element?
- Is the focus indicator visible at all times?
- Can you open/close dropdown menus with Enter/Space and Escape?
- Does the tab order follow the visual layout?
Step 2: Screen Reader Spot-Check
- Windows: NVDA (free, nvaccess.org)
- Mac/iOS: VoiceOver (built in — Cmd+F5)
- Android: TalkBack (Settings → Accessibility)
Step 3: 200% Zoom Test
Press Ctrl/Cmd + "+" until the page is at 200% zoom. Check that no text overlaps, the layout holds, and all content remains accessible without horizontal scrolling.
Step 4: Mobile Tap Targets
WCAG 2.2 introduced criterion 2.5.8: all clickable targets must be at least 24×24 CSS pixels. On your phone, try tapping every link, button, and form field.
Step 5: Colour and Contrast Manual Review
Automated tools miss text over images, hover state contrast, placeholder text, and error message contrast. Use the WebAIM Contrast Checker. Target is 4.5:1 for normal text and 3:1 for large text.
How Do You Prioritise What to Fix First?
Fix critical issues with low effort first — missing alt text, low contrast, and empty links take minutes to fix. Then plan high-effort critical fixes like keyboard traps and inaccessible forms.
| Priority | Impact | Examples | Action |
|---|---|---|---|
| Fix immediately | Critical/High | Missing alt text, low contrast, empty links | This week |
| Plan this sprint | Critical/High | Keyboard traps, inaccessible forms | 1–2 weeks |
| Weekly maintenance | Medium/Low | Link text improvements, heading fixes | Regular workflow |
| Next release | Medium/Low | Custom components, CMS templates | Next dev cycle |
What Does Remediation Cost in the UK?
| Service | Typical UK Price | What You Get |
|---|---|---|
| Quick-win sprint | £1,500–£4,000 | Fix most common issues |
| Professional audit | £600–£5,000+ | Manual + automated testing |
| Full remediation | £2,500–£6,000+ | Fix and verify compliance |
Need professional help?
We offer an accessibility audit from £19.99 on eBay and a full website audit for £299.
How Do You Build Accessibility Into Your Workflow?
Don't treat accessibility as a one-off project. Run automated scans monthly, manual tests quarterly, and a professional audit annually. Never use overlay widgets.
The Anti-Overlay Warning
- The FTC fined accessiBe $1 million in 2025 for deceptive claims
- 25% of ADA lawsuits in 2024 targeted sites using overlay widgets
- The disability community widely rejects overlays — they add noise and don't fix underlying code
- Fix the source HTML and CSS — it's the only approach that works
Does Improving Accessibility Actually Help SEO?
Yes. Accessibility and SEO share technical foundations. One study found accessible sites saw 23% more organic traffic and 27% more keyword rankings.
| Accessibility Practice | SEO Benefit |
|---|---|
| Descriptive alt text | Image search visibility |
| Semantic heading structure | Better crawlability |
| Descriptive link text | Stronger internal linking |
| Clean, valid HTML | Faster page speed |
Your Free Weekend Accessibility Sprint
You can make meaningful accessibility progress in a single weekend. Saturday morning: run WAVE and Lighthouse. Saturday afternoon: fix structure. Sunday: manual testing.
Saturday Morning (2–3 hours)
- Install WAVE and axe DevTools browser extensions
- Run WAVE on your top 5 pages
- Fix every contrast error and missing alt text
- Run Lighthouse on the same pages
Saturday Afternoon (2–3 hours)
- Fix every form label issue
- Replace "Click here" with descriptive text
- Check heading structure — one H1 per page
- Add lang="en" to your html tag
Sunday (2–3 hours)
- Unplug mouse, Tab through entire site
- Install NVDA or VoiceOver, spot-check
- Zoom to 200%, check layout
- Publish an accessibility statement
Resources
- WebAIM Contrast Checker — test colour pairs
- WAVE browser extension — visual page scanner
- axe DevTools — developer accessibility testing
- NVDA screen reader — free Windows screen reader
- WCAG 2.2 Quick Reference
- Daedalus AI Accessibility Check — free automated scan
Frequently Asked Questions
What free tools can I use to test my website accessibility?
The three best free tools are WAVE (visual overlay), axe DevTools (zero false positives, developer-friendly), and Google Lighthouse (built into Chrome). For command-line automation, Pa11y is free and open source.
Do I need a professional accessibility audit or can I do it myself?
For small business sites under 15 pages, you can do a useful initial audit yourself. A professional audit for a small site costs £600–£1,200 and catches 90%+ of issues vs. 30–57% for automated tools alone.
What are accessibility overlay widgets and should I use one?
They inject JavaScript that claims to fix accessibility issues. They do not fix underlying code. The FTC fined accessiBe $1 million. The disability community widely rejects these tools. Fix the source HTML and CSS instead.
How often should I test my website for accessibility?
Run automated scans on your highest-traffic pages monthly. Perform manual keyboard and screen reader testing quarterly. Conduct a full professional audit annually.
Does improving accessibility help my SEO rankings?
Yes. One study found that websites with strong accessibility saw 23% more organic traffic and 27% more keyword rankings.
How long does it take to fix accessibility issues?
The most common issues can be fixed in 4–8 hours over a weekend. A full accessibility sprint typically takes 2–4 weeks of part-time effort.
Ready to Make Your Website Accessible?
Continue reading: Last week: WCAG 2.2 Quick Wins | Next week: Accessibility Statements & Legal Compliance (Part 3 of 4)
This guide is for informational purposes and does not constitute legal advice. For specific compliance questions, consult a qualified solicitor specialising in digital accessibility law.