Web accessibility isn't optional anymore — it's expected, increasingly mandated, and just good engineering. But the tools you need don't have to cost $100/month. Here's a curated list of the best free accessibility tools for developers, tested and verified in 2026.
🎨 Start with Contrast Checking
Color contrast is the #1 accessibility issue. Check your colors instantly — free, no signup.
Open Contrast Checker →1. Color Contrast Checkers
🎨 Korpo.Pro Color Contrast Checker FREE
Our own tool — and we're biased, but here's why it's good: it uses the official WCAG 2.1 relative luminance formula, supports both color picker and manual hex input, shows a live preview of your colors, and gives you pass/fail for AA and AAA at both normal and large text sizes. No ads, no signup, no limits.
Try Contrast Checker →WebAIM Contrast Checker
The gold standard that's been around for years. WebAIM's tool is simple: two color inputs, instant ratio, pass/fail table. No live preview, but it's rock-solid reliable. Best used alongside a browser color picker extension.
Stark (Figma/Chrome Plugin)
Stark integrates directly into Figma, Sketch, and Chrome. Designers love it because you check contrast without leaving your design tool. The free tier covers basic contrast checking; advanced features (focus order, landmark detection) require the Pro plan ($60/year).
2. HTML & Accessibility Validators
WAVE (Web Accessibility Evaluation Tool)
WAVE is the most popular free accessibility checker — and for good reason. Paste any URL and it overlays icons directly onto your page showing errors, alerts, features, and structural elements. The sidebar breaks down every issue with explanations. No account needed.
axe DevTools (Free Browser Extension)
Deque's axe engine is what powers Lighthouse's accessibility audits. The free Chrome/Firefox extension runs in DevTools and finds ~57% of WCAG issues automatically. It's the same engine used by enterprises — just without the reporting dashboard.
Lighthouse (Built into Chrome)
Open Chrome DevTools → Lighthouse tab → Generate report. Lighthouse audits accessibility alongside performance, SEO, and best practices. It catches contrast issues, missing alt text, ARIA problems, and heading structure. Free and already in your browser.
3. Screen Reader Testing
NVDA (Windows) / VoiceOver (Mac)
You don't need to buy JAWS ($1,000+) to test screen reader compatibility. NVDA is free and open source for Windows; VoiceOver is built into every Mac. Spend 10 minutes navigating your site with one of these and you'll find issues no automated tool catches — focus order problems, missing labels, confusing link text.
ChromeVox (Chrome Extension)
Google's screen reader extension for Chrome. Lighter weight than a full screen reader — good for quick checks during development, but don't rely on it exclusively. Real NVDA/VoiceOver testing is still essential.
4. Full-Site Auditing
📋 Korpo.Pro Bulk Domain Checker FREE
While not a traditional accessibility tool, our bulk domain checker lets you audit email deliverability across multiple domains simultaneously. For accessibility, combine it with our SEO analyzer to check meta tags, headings, and structure across your site. Both are free with no signup.
Try Bulk Checker →Microsoft Accessibility Insights
Microsoft's free tool comes in two flavors: Accessibility Insights for Web (Chrome extension) and Accessibility Insights for Windows (desktop app). The FastPass feature runs automated checks in ~30 seconds. The Assessment feature walks you through manual testing steps — great for WCAG 2.1 AA compliance audits.
5. Developer Utilities
🎯 tota11y (Khan Academy)
Drop a single JavaScript snippet into your page and tota11y overlays an accessibility visualization toolbar. It annotates headings, landmarks, link text, contrast, and form labels — directly on the page. Great for catching issues during development before they reach production.
ARC Toolkit (TPGi)
A Chrome DevTools panel from the accessibility consultancy TPGi. More technical than WAVE — shows the accessibility tree, ARIA mappings, and computed properties. For developers who want to understand why something fails, not just that it fails.
Putting It Together: A Free Accessibility Workflow
Here's how to combine these tools into a practical, free workflow:
- Design phase: Use our contrast checker to validate your color palette before writing any CSS. Check every text/background pair.
- Development: Install axe DevTools and run it on every new component or page. Fix issues before they accumulate.
- Pre-launch: Run Lighthouse audit. Manually test with NVDA or VoiceOver for 10 minutes. Check all forms and interactive elements.
- Production: Run WAVE on key pages weekly. Use bulk checker to monitor domain health. Set up Lighthouse CI in your pipeline for automated regression testing.
- Ongoing: Re-check after any design change or major update. Accessibility degrades silently — the only way to stay compliant is to check regularly.
🚀 Start Your Accessibility Audit
Check your colors, audit your domains, and scan your SEO — all free, all on one platform.
FAQ
Are these tools really free?
Yes — every tool listed has a genuinely free tier. Some (Stark, ARC Toolkit) have paid upgrades for teams, but the core accessibility testing features are free. Our Korpo.Pro tools are 100% free with no paid-upsell for the web interface — Pro is only for API access and bulk monitoring.
Do automated tools catch everything?
No. Automated tools catch ~30-57% of WCAG issues. The rest requires manual testing — keyboard navigation, screen reader testing, and content review. Use automated tools as a first pass, not a substitute for testing.
Which tool should I start with?
Start with our color contrast checker — contrast is the most common and easiest-to-fix issue. Then install axe DevTools for your browser. Those two alone will catch 90% of the low-hanging accessibility problems.