HTML_CodeSniffer
HTML_CodeSniffer: A focused, developer-oriented checker for WCAG, Section 508, and custom standards. Ranked #115 of 129 in Website Accessibility Tools by our editors (3.0/10); pricing: Open source; best for developers checking HTML standards in code.
At a glance
- Editor score3.0 / 10
- PricingOpen source
- Best forDevelopers checking HTML standards in code
- Paid fromFree
- WCAG versionWcag 2.1
- Facts checked21 Sep 2026
Where it wins
- Checks WCAG 2.1 Levels A, AA, and AAA
- Runs client-side with bookmarklet, Node.js, and headless options
- Supports custom accessibility standards and sniffs
Where it doesn't
- Focused on page and source checks rather than recurring scans
- No documented integrations or external API
- Requires developer-oriented JavaScript or command-line workflows
Our verdict on HTML_CodeSniffer
HTML_CodeSniffer is an open-source JavaScript accessibility checker for developers testing web content and markup. It analyzes HTML documents, source code, or the current web page, then reports known and potential violations against WCAG 2.1 Levels A, AA, and AAA, as well as web-related Section 508 requirements. Its client-side design keeps processing in JavaScript without server-side processing, making it suited to teams that want an inspectable tool for accessibility checks in development workflows.
Its standout strength is the range of ways developers can invoke the checker. A bookmarklet can audit a web page, while direct JavaScript calls can return detected violations for use in custom tooling. The product can also run through headless browsers from the command line and can be installed as a Node.js module. Custom accessibility standards and sniffs extend the checker beyond its built-in coverage, which gives development teams more control over how markup is evaluated.
HTML_CodeSniffer is a focused choice for page and source analysis rather than a broader accessibility management platform. The published capabilities do not center on recurring scans, integrations, or an external API, so teams seeking scheduled monitoring or connected workflows should consider alternatives built around those needs. Choose HTML_CodeSniffer when developer control, client-side processing, WCAG 2.1 coverage, and customizable checks matter most. It is less suitable for organizations that want a managed service with ongoing automated monitoring or a wider platform ecosystem.
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HTML_CodeSniffer pricing
HTML_CodeSniffer fact sheet
| Free plan | Not verified |
|---|---|
| Paid from | Free |
| WCAG version | Wcag 2.1 |
| Scan scope | Page |
| Scan limit | Not verified |
| Scheduled scans | Not verified |
| Browser extension | No |
| CI/CD integration | Not verified |
| API access | Yes |
| Deployment | Cloud |
| Platforms | Web |
| Support | Docs |
| Pricing | Open source |
| Website | squizlabs.github.io |
| Facts checked | 21 Sep 2026 |
Alternatives to HTML_CodeSniffer
- Octopus Scanner (formerly A11y Scanner)A free desktop scanner for detailed local audits of complex websites.9.3
- WAVEA flexible accessibility suite spanning free page checks, browser extensions, APIs, and CI workflows.9.1
- IBM Equal Access Accessibility CheckerA technically focused toolkit for browser, batch, and CI/CD accessibility checks.9.0
See all HTML_CodeSniffer alternatives →
Also Ranked In
HTML_CodeSniffer is ranked in 2 of our directories.
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Featured on iTechGuides
HTML_CodeSniffer is listed in our Website Accessibility Tools directory. Add the badge to your site — it links back to this page.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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