You don't need a procurement request, a vendor demo, or a line item in next quarter's budget to start finding real accessibility bugs on your site. You need a browser tab, about fifteen minutes, and a cup of coffee that's still hot when you finish. That's it.
The tools below are free, they install in under a minute, and they surface the kind of issues that actually block real users — not hypothetical ones. None of them will catch everything (more on that in a second), but together they'll catch far more than most teams assume, and they'll do it before your next standup.
The Stat: Automated testing catches 57% of accessibility issues by volume, according to an analysis of more than 2,000 audits, 13,000+ pages, and roughly 300,000 individual issues. (Source: Deque Automated Accessibility Coverage Report)
That 57% figure is the whole reason this list exists in two parts. Automated scanners are extraordinary at finding the mechanical, rule-based stuff — missing alt text, bad color contrast, malformed ARIA, unlabeled form fields. But well over a third of real issues (things like whether a focus order actually makes sense, or whether an error message is genuinely understandable) only show up when a human interacts with the page. So the list below has four scanners and one tool that's already in your hands: your own keyboard.
The Five Tools, in the Order You Should Run Them
1. axe DevTools — your first pass, every time
axe DevTools is a free browser extension for Chrome, Firefox, and Edge that runs the same axe-core rules engine used inside most enterprise accessibility platforms. Install it, open your DevTools panel, click "Scan," and it returns a prioritized list of issues with the exact DOM node, the WCAG success criterion it violates, and a plain-language fix. It has one of the lowest false-positive rates of any free scanner, which matters when you're trying to convince a skeptical teammate that a flagged issue is real.
Do this today: run it on your homepage and your primary conversion page (checkout, signup, or contact form). Fix anything flagged as "critical" or "serious" first — those are almost always contrast failures, missing form labels, or broken heading structure.
2. WAVE — see the problem, not just read about it
WAVE takes a different approach: instead of a report panel, it overlays icons directly on your live page showing exactly where each issue lives — a red icon over an image with no alt text, a yellow icon over a low-contrast heading. This visual-first format is genuinely useful for design and content teams who don't think in DOM trees. It's available as a browser extension or as a plug-in-your-URL web tool, no install required if you just want a quick check.
Do this today: paste your URL into the web version and look specifically at the "Contrast Errors" and "Alerts" tabs — these catch things axe sometimes phrases more technically, like ambiguous link text or empty headings.
3. Lighthouse — the one already built into your browser
You don't even need to install anything for this one. Lighthouse's accessibility audit ships inside Chrome DevTools (Chrome menu → More Tools → Developer Tools → Lighthouse tab). It scores your page 0–100 on accessibility and bundles the score alongside performance and SEO, which makes it an easy sell when you need a stakeholder-friendly number rather than a raw issue list. It's built on a subset of the same axe-core rules, so treat a low Lighthouse score as a signal to dig deeper with axe DevTools or WAVE, not as the final word.
Do this today: run it in an incognito window (extensions can skew the score) and screenshot the score for your next design review — a number people can compare over time is often what actually gets fixes prioritized.
4. Microsoft's Accessibility Insights — for tab-order and focus bugs
Microsoft's Accessibility Insights is the tool to reach for once the "easy" automated fixes are done. Its FastPass feature runs an automated scan like the others, but its real value is the "Tab stops" visualizer — it draws the literal path your keyboard focus takes across the page, in order, as numbered lines. This is one of the fastest ways to spot a focus order that jumps illogically around the page, or a custom dropdown that silently swallows keyboard focus and never gives it back.
Do this today: run Tab Stops on any page with a custom widget — a modal, a carousel, a mega-menu — and watch where the numbered path goes. If it skips visible content or loops back on itself, that's a real bug a screen reader or keyboard-only user will hit immediately.
5. Your own keyboard — the tool none of the scanners can replace
Unplug your mouse for five minutes. Load your homepage and press Tab repeatedly. Can you always see, with your own eyes, which element currently has focus? Can you reach every interactive control — every link, button, and form field — without ever touching a mouse? Can you open and close a modal, then land back where you started, using only Escape and Tab?
This is the test that catches the 43% automated tools miss by design, because "does this make logical sense to a human" isn't something a rules engine can evaluate. It costs nothing and takes less time than your coffee takes to cool.
Quick Reference: Which Tool for Which Job
| Tool | Best for | Install time |
|---|---|---|
| axe DevTools | First-pass scan, low false positives | ~1 min (extension) |
| WAVE | Visual overlay for non-developers | 0 min (web) or ~1 min (extension) |
| Lighthouse's accessibility audit | Stakeholder-friendly score, already built in | 0 min |
| Microsoft's Accessibility Insights | Tab order and focus-trap bugs | ~1 min (extension) |
| Your own keyboard | Everything the others structurally can't see | 0 min |
- Run axe DevTools on your homepage and one conversion page
- Run WAVE and review the Contrast and Alerts tabs
- Check your Lighthouse accessibility score in an incognito window
- Run Accessibility Insights' Tab Stops on any custom widget
- Unplug your mouse and Tab through the entire page yourself
One more habit worth building: run this five-tool pass more than once. A homepage that scans clean today can regress the moment someone ships a new hero banner without alt text, or a designer swaps a button color and quietly drops it below the contrast threshold. Automated scanners are fast enough that there's no excuse for treating this as a once-a-year event — bookmark this list, and re-run it after any significant redesign, new landing page, or major content push. The teams that stay accessible aren't the ones who scanned once and moved on; they're the ones who made scanning a five-minute habit.
Run all five and you'll walk away with a real, prioritized punch list — most of it fixable before lunch, some of it worth flagging to your dev team for the next sprint. None of this replaces a full manual audit against every WCAG success criterion, and none of these tools can tell you whether your site would survive a demand letter. But it's fifteen minutes, it's free, and it beats not checking at all.
If you want to know what's hiding in that other 43%, that's exactly the gap a real audit exists to close. Want the issues these free tools can't catch? You can get a free automated scan of your homepage and see where the manual review needs to start.