Website accessibility checker Chrome extension: which to install and how to use it

The best website accessibility checker Chrome extension for most small business owners is WAVE for a quick visual look at one page, axe DevTools for a precise error list with the code to fix, and Lighthouse, which is already inside Chrome, for a fast score. All three are free, none needs an account, and they find the kinds of error that sit behind most accessibility complaints. This guide compares them, shows the steps to run a scan, says what to do with the results, and covers what no extension can check.

The website accessibility checker Chrome extensions worth installing

Features and free limits change; some tools add paid tiers. Checked from the tools' own pages and store listings on 2026-11-15, and worth confirming before you rely on a feature.

How to run a scan, step by step

1. Pick the page. Start with the home page, then one page with a form (contact or checkout) and one content page.
2. Install one extension from the Chrome Web Store. Start with WAVE or axe DevTools; add a second later for a cross-check.
3. Open the page in the state a visitor sees. Close cookie banners last, not first: they are part of what a keyboard user meets.
4. Run the scan. WAVE: click its icon. axe DevTools: press F12, open the axe tab and choose the scan button. Lighthouse: F12, Lighthouse tab, tick Accessibility only, then generate the report.
5. Save the result. Take a screenshot or export it with the date. It is your before.
6. Sort by what is easy. Colour contrast, missing alt text, missing form labels and empty buttons or links are the usual fast wins.
7. Fix, then rescan the same page. The count should fall; the new report is your after.

What each extension tells you

WAVE

WAVE draws small icons right on your page: red for errors, yellow for alerts, green for features that help (a correct alt text, a label). That makes it the easiest for a non-developer to read, because you can see which button or image the problem belongs to. Its contrast tab lists each failing pair of colours. WAVE alerts are not all errors; treat yellow items as a to-check list, not a failure.

axe DevTools

axe lists issues by rule with the element's code, a plain description and a suggested fix. It is built on the open-source axe-core engine, which many testing tools use. It is the one to hand to a developer. Some guided tests and saved reports sit in the paid version, so read what the free version includes.

Lighthouse

Lighthouse gives the accessibility section a score out of 100 and a list of passes and failures. It is useful for tracking a number over time and for a quick yes or no. A score of 100 does not mean accessible; it means the automated checks it runs passed, which are a subset.

Accessibility Insights for Web

The quick check runs automated rules; the assessment walks you through manual tests such as tabbing through the page and checking focus order, which is where automated tools stop. It takes longer, and it finds more.

How much do the extensions miss?

Automated checkers can only test what a program can decide. Deque published a study of audits in which its automated rules found about 57% of issues by volume, and the rest needed a human to judge. Other groups quote lower figures for the share of success criteria that can be fully automated. The takeaway is the same: a clean scan is a good sign and not a pass.

• Alt text quality. A tool sees that alt text exists, not whether it describes the picture.
• Keyboard use. Whether you can open a menu, close a popup and see where focus is needs a person pressing keys.
• Screen reader sense. Whether the reading order and announcements make sense.
• Link purpose. "Click here" passes a scan and fails a person.
• Video and audio. Captions and transcripts.
• Whole site. An extension scans the page you have open, not your site. A 40-page site needs 40 scans, or a scanner that crawls.

A five-minute keyboard test to add to every scan

After the extension, do this: put the mouse away. Press Tab from the top of the page. Can you see where focus is at every step? Can you reach the menu, open a link and press Enter on a button? Does a popup trap you, or let you close it with Escape? Can you fill and send the contact form? Write down where it breaks. These notes catch problems the extension cannot, and cost nothing. Our ADA compliant website checklist turns this into 25 checks you can run in a week.

Common problems when using a Chrome extension checker

• The scan runs before the page finishes loading. Wait until menus, sliders and widgets appear, then scan; otherwise parts of the page are missing from the result.
• Hidden content is skipped. A menu that opens on click, a modal or a tab panel is not tested until you open it. Open each state and scan again.
• Mobile layouts differ. Use Chrome's device toolbar to narrow the window, then scan, because a collapsed menu has its own errors.
• Other extensions interfere. Ad blockers and page-modifying extensions can change what you scan. Try a fresh Chrome profile or a private window with only the checker enabled.
• Counts differ between tools. One tool counts every failing element, another groups them by rule. Compare which rules fail, not the totals.
• Pages behind a login. The extension works on them when you are signed in, which crawling scanners cannot do, so it is the right tool for an account or checkout page.

A practical routine for a small site: scan five pages with one extension on a Monday, fix the three most common errors, rescan on Friday and keep both reports. Over a month that is a record you can quote in a statement, and you will know when a plugin update breaks something.

Which extension to use for which job

What to do with the results

Group the errors by cause, not by page. Ten pages that all fail contrast usually share one colour in the theme, and one edit clears them. Missing alt text is a content job you can hand to whoever writes the pages. Form labels and icon names are usually a template change. After fixing, publish an honest note on what you tested and when; our accessibility statement template has wording. If you hit errors you cannot place, the website accessibility checker free guide covers the web-based scanners, and website accessibility audit cost says when to pay for an expert.

One caution: a browser extension is a tool for you. Do not add an extension to your site's visitors' experience and call it compliance. We are not lawyers, and this is not legal advice.

Frequently asked questions

What is the best free accessibility checker for Chrome?

WAVE and axe DevTools are the two most used. WAVE is easier to read; axe gives developers more detail. Lighthouse needs no install.

Does Chrome have a built-in accessibility checker?

Yes. Lighthouse in developer tools includes an accessibility audit, and the Elements panel shows the accessibility tree and contrast ratios for colours you pick.

Can an extension tell me if my site is ADA compliant?

No. It finds machine-detectable errors on one page. Compliance is judged on how people use the whole site, usually against WCAG 2.1 AA.

Do accessibility extensions work on every page?

They scan the page loaded in your tab, including pages behind a login if you are signed in. They do not crawl links by themselves.

Should I run more than one checker?

Yes. Different tools use different rules, so a second scan catches things the first misses. Do not expect them to agree on counts.

How often should I scan?

After every theme, plugin or content change that affects layout, and at least monthly for pages that change often.

Sources

• WebAIM, WAVE browser extension page (checked 2026-11-15).
• Deque, axe DevTools extension page and axe-core documentation; Deque study on automated issue coverage, 2021.
• Google Chrome for Developers, Lighthouse accessibility audits.
• Microsoft, Accessibility Insights for Web documentation.
• W3C, Web Content Accessibility Guidelines 2.1.