Website accessibility checker: 12 tools compared on the same terms (2026)

What should you look for in an accessibility checker?

Most tools run similar rule sets. What sets them apart is less the number of rules and more where the tool fits into your workflow. Five questions are enough:

1. Coverage: does it test one page at a time, or crawl all of your pages (or samples from each template)?
2. Engine: which rule engine runs underneath? axe-core (Deque, open source), HTML_CodeSniffer or the vendor's own. The same page can give different results in two engines.
3. Output: does each finding come with its location (a selector or code snippet) and a WCAG criterion? Is the fix advice a general explanation or a code example?
4. Monitoring: does the scan repeat on a schedule, and does it tell you when a fixed issue comes back (a regression)?
5. Overlay: does the vendor also sell a product that adds a widget on top of your site? That can shape how the scan results are presented to you.

We compared 12 tools on these five questions, based on what each vendor says on its own pages. We only quote prices where the vendor publishes them; prices change, so check the vendor's page before you buy.

Source: W3C WAI, Deque Systems, GitHub, Pa11y

12 website accessibility checkers in one table

Source: WebAIM, WebAIM, Deque Systems, Chrome for Developers (Google), Pa11y, Siteimprove Help Center, Silktide, accessiBe, PR Newswire, UserWay, AudioEye, Equally AI

Which free accessibility checker should you use, and when?

If you're looking at one page, you don't need a paid tool. The free tools don't replace each other; each is good at a different job:

• WAVE: shows issues as icons on top of the page. The easiest option for people who don't read code, such as content editors and designers. For many pages, WebAIM's API runs on credits: 100 for a new account, then $0.04 per credit for 250–999 credits ($10 minimum).
• axe DevTools: the developer's tool. It runs in the browser's developer tools and maps each finding to an element in the code. Its engine, axe-core, is the open-source library many other tools also use.
• Lighthouse: already in Chrome. Its accessibility score is a weighted average of axe-core audits, weighted by axe's impact ratings. A quick indicator, not a substitute for a full axe scan.
• Pa11y: runs from the command line or inside Node.js, so it suits automated tests before deployment (CI). Its default runner is HTML_CodeSniffer, with axe as an option; the default standard is WCAG2AA.
• Siteimprove and Silktide extensions: because they run in your browser, you can test pages behind a login and multi-step forms. Siteimprove's extension uses the same engine as its paid platform.

A practical starting point: a developer begins with axe DevTools or Pa11y, a content owner with WAVE. Running the same page through two different engines can catch what one of them misses.

Source: WebAIM, WebAIM, Deque Systems, Chrome for Developers (Google), Pa11y, Siteimprove Help Center, Silktide

What do paid accessibility platforms add?

Free extensions test the page that's open in front of you. In Silktide's own words, free checkers test a single page at a time, while paid platforms automatically test every page on your site. The main additions:

• Site-wide scanning: hundreds of pages, sometimes PDFs too.
• Scheduling and regression alerts: you hear about it when a theme update brings back an issue you'd fixed.
• Prioritisation and reporting: a dated record you can show to management or an auditor.
• Team workflow: task assignment, permissions and, on some platforms, expert audit services.

Enterprise platforms (Siteimprove, Silktide, Deque) are built for many sites and large teams. A single shop or company site may not need all of that; when you ask for a demo, ask about page limits and scan frequency.

Source: Silktide, Siteimprove Help Center

Should you use the overlay vendors' free scanners?

You can; the findings often point to real issues. What to watch is the solution the report steers you towards. accessiBe, UserWay, AudioEye and Equally AI all sell widgets that are added on top of the site with a line of JavaScript. That layer doesn't change your site's source code.

On 22 April 2025, the US Federal Trade Commission (FTC) approved its final order against accessiBe: the company must pay $1 million and can't claim without evidence that its product makes any website WCAG-compliant. In May 2023, the European Disability Forum (EDF) and IAAP stated that overlays don't make a site compliant with EU legislation. According to UsableNet's 2025 data, lawsuits against companies using accessibility widgets continued all year and peaked above 150 in a single month.

Our advice: take the scanner's list of findings and fix them at the source (theme, component, content). More in our post on overlays.

Source: US Federal Trade Commission (FTC), EDF and IAAP, UsableNet

Where does AccessibleOrNot fit in this table?

We put our own product in the same columns. Here are its gaps too.

• Engine: axe-core. So we have the same limit as the free tools above: we find what can be found automatically and give you a manual checklist for the rest.
• What we don't do: we have no browser extension, and we don't scan pages behind a login (public pages only). We're a new product, founded in 2026.
• What we do: we group pages by template (product, category, cart, checkout) and scan samples from each, so an issue that comes from the same code is listed once. Each finding comes with a before/after code example and panel notes for Shopify, WooCommerce, Shopware, ikas and Ticimax. We split findings into EAA (WCAG 2.1 AA) and Türkiye Circular (WCAG 2.2 A) views. Paid plans add a weekly scan and regression alerts.

If another tool fits better, choose it: if your developers want a test on every code change, a paid axe DevTools plan or Pa11y CI; if you manage hundreds of sites and PDFs, Siteimprove or Silktide; for a quick look at one page, WAVE.

Source: Deque Systems