Free ADA compliance checkers: what they can and can't tell you

Search for a “free ADA compliance checker” and you'll find dozens of tools that scan a page and return a score or a list of errors. Many of them are genuinely useful. None of them can tell you that your website is “ADA compliant”, and none can make it so. Whether it's sold as an “ADA compliant website checker” or simply a free ADA website checker, the same limits apply. Here's what they actually do, where they help, and where a person still needs to look.

Not legal advice. We test websites against the Web Content Accessibility Guidelines (WCAG). We're not lawyers, and this guide doesn't say what any law requires of your business. For legal questions, talk to a qualified attorney.

What a free checker actually checks

Most free checkers run an automated rules engine, such as the open-source axe-core, WAVE, or HTML_CodeSniffer, against the code of one page. They compare what they find with a set of rules based on WCAG, the technical standard most accessibility work is measured against. They're good at spotting problems that can be detected in code, for example:

• Images with no alt attribute
• Form fields with no label
• Links and buttons with no readable name
• Text with too little color contrast
• A page with no declared language or no title

These issues are common, so a scan is a sensible first step. In a coverage report based on more than 13,000 audited pages, Deque, the company behind axe-core, found that its automated tests identified 57% of the total issues in first-time audits (Deque's Automated Accessibility Coverage Report). The same report found automated issues for only 16 of the 50 WCAG 2.1 Level AA success criteria.

What a free checker can't tell you

Many accessibility questions need human judgement. A scanner can see that an image has alt text, but not whether the text makes sense. It can't tell whether a menu works with only a keyboard, whether focus moves to a pop-up when it opens, whether error messages are clear, or whether a screen reader user can actually finish your booking form.

When the UK Government Digital Service built a test page with 143 deliberate accessibility barriers and ran 10 free tools against it, 29% of the barriers weren't found by any of the tools, and the best single tool found 41% (GOV.UK accessibility blog, 2017). Their advice was to combine automated tools with manual checking.

So a clean scan is good news, but it doesn't mean a page is accessible, and a score of 100 isn't a certificate. Be wary of any tool or widget that promises to make your site “compliant” automatically. Our guide to accessibility overlays explains why we don't recommend them.

How to use a free checker well

1. Scan the pages that matter most. Your home page, contact or booking page, and any checkout or sign-up form.
2. Fix the clear-cut issues first. Missing alt text, missing labels, empty links and low contrast are usually quick to fix and help a lot of people.
3. Then test by hand. Put the mouse away and use Tab, Shift+Tab, Enter and Space to move through the page. Can you see where you are at every step? Can you reach and use everything? Our guide to manual accessibility testing walks through it.
4. Try a screen reader on one key task. NVDA on Windows is free, and VoiceOver is built into Macs and iPhones.
5. Rescan after changes. New content, themes and plugins can bring issues back.

When it's worth getting help

If you'd like someone to do the manual part, or to explain the scan results in plain English, that's what an audit is for. You can ask us for a free one-page snapshot: three real issues from your home page with screenshots and fixes, from an automated scan plus a quick keyboard check. Our $299 Snapshot Audit adds manual keyboard and screen reader testing on up to three pages. You can see what our reports look like in the sample report.

Prefer to start on your own? Run our free accessibility checker on one page.

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