WAVE vs Lighthouse 2026 | Free Accessibility Checker Comparison
Last updated: 2026-07-09
WAVE by WebAIM and Google Lighthouse are the two free accessibility checkers that most non-developers reach for first, because both are approachable and require no budget or coding skill. They take very different approaches, though, and understanding the difference helps you get real value rather than a false sense of security. WAVE is a visual, in-page tool: you install a browser extension (or paste a URL into the online version) and it overlays icons directly on your page showing exactly where each error, alert, and structural feature sits. Lighthouse is built into the Chrome browser's DevTools and produces a scored report — it runs the axe accessibility engine behind the scenes and gives you a single number from 0 to 100 alongside a list of failed checks. WAVE is oriented toward seeing and understanding issues in context, while Lighthouse is oriented toward a quick pass/fail score you can track over time. Neither replaces manual testing, and both check only a limited slice of WCAG. This comparison explains how each works, what each catches and misses, and which is the better starting point depending on how you like to work.
At a Glance
| Feature | WAVE | Google Lighthouse |
|---|---|---|
| How results are shown | Visual icons and annotations overlaid on the live page | Scored report (0-100) with a list of failed checks in DevTools |
| Underlying engine | WebAIM's own WAVE engine | axe-core (Deque) via the Lighthouse accessibility audits |
| Page structure view | Excellent — heading order, landmarks, and reading order shown visually | Limited — focuses on rule pass/fail, not structural overview |
| Best for non-developers | Yes — designed to be understood without technical skill | Partly — the score is simple, but fixing issues assumes some technical context |
| Single overall score | No — counts of errors, alerts, and features instead | Yes — a single 0-100 accessibility score |
| CI/CD automation | Paid API only | Free — runs from CLI and in pipelines |
| WCAG coverage | Automated subset only (~30-40% of criteria); manual testing still required | Automated subset only (~30-40% of criteria); manual testing still required |
| Data privacy | Extension runs locally; safe for sensitive pages | Runs locally in Chrome; PageSpeed Insights version fetches the page remotely |
WAVE
Pros
- Visual overlay places icons and annotations directly on the page, so you see exactly where each issue lives instead of reading an abstract list — ideal for non-developers
- Shows page structure at a glance, including heading hierarchy, landmark regions, and reading order, which helps catch structural problems automated scores often hide
- Extremely low learning curve: anyone can run it in seconds and interpret the colored icons without technical training
- The browser extension runs entirely on your machine with no data sent to a server, making it safe to test password-protected or sensitive pages
Cons
- Flags a fair number of 'alerts' that are not definite violations, so you need human judgment to separate real problems from advisory warnings
- No single score to track progress over time, which some teams want for reporting
- Limited handling of dynamic, JavaScript-driven content — it largely evaluates the DOM at the moment you scan
- Does not integrate into a build pipeline in the free version; automated/CI testing requires the paid API
Google Lighthouse
Pros
- Produces a single 0-100 accessibility score plus performance, SEO, and best-practices scores in the same report, which is convenient for quick health checks
- Built directly into Chrome DevTools and PageSpeed Insights, so there is nothing extra to install for most users
- Uses the axe-core engine under the hood, meaning its underlying checks are the same industry-standard rules many professional tools rely on
- Runs from the command line and in CI/CD pipelines, so developers can automate accessibility checks and track the score across releases
Cons
- The single score is dangerously reassuring — a high number reflects only the ~30-40% of WCAG that can be automated, so a 95+ score does not mean the site is accessible or lawsuit-safe
- Results are a list in the DevTools panel; it does not visually highlight where issues appear on the page the way WAVE does
- Weaker at surfacing structural and reading-order context, since it focuses on scored rule pass/fail rather than page architecture
- Can produce different scores on repeated runs of dynamic pages, and it evaluates a single rendered snapshot rather than user interactions
Our Verdict
WAVE and Lighthouse are both excellent free starting points, and the smartest approach is to use them together because they answer different questions. Lighthouse gives you a quick, repeatable score you can track release over release and automate in a pipeline — great for spotting regressions and for a fast health check. WAVE shows you where problems actually live on the page and reveals the heading and landmark structure that a numeric score hides, which makes it far better for understanding and fixing issues, especially if you are not a developer. Our recommendation: use Lighthouse for the at-a-glance score and automation, and use WAVE when you sit down to actually understand and remediate what is wrong. The single most important caveat applies to both: they only test the roughly 30-40% of WCAG criteria that can be checked automatically. A perfect Lighthouse score or a clean WAVE report does not mean your site is accessible or safe from an ADA demand letter — keyboard operability, screen reader experience, meaningful alt text, and logical focus order all require manual testing with real assistive technology. Treat these tools as the first 20 minutes of the job, not the whole job.
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