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SPECIFICTION
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HTML_CodeSniffer

squizlabs.github.io

WebWindowsmacOSLinuxAPISelf-hosted
Visit squizlabs.github.io
Spec score 7.4 #135 of 169 in Accessibility Testing Software

Spec sheet

Purpose
HTML_CodeSniffer checks HTML source code for violations of a defined coding standard.Read 12 Oct 2026 · squizlabs.github.io
Support
The project README directs users to its GitHub issue tracker to report problems and welcomes contributions through pull requests.Read 12 Oct 2026 · github.com
License
The GitHub repository identifies the project license as BSD 3-Clause.Read 12 Oct 2026 · github.com
Accessibility standards
It includes checks for WCAG 2.1 Levels A, AA, and AAA, and Section 508.Read 12 Oct 2026 · squizlabs.github.io
API access
YesRead 21 Sep 2026 · squizlabs.github.io
Auditor feedback
The auditor displays messages emitted by a standard and, where possible, points to the HTML element causing an issue.Read 12 Oct 2026 · github.com
Bookmarklet
Its auditor bookmarklet can run accessibility checks on web pages and is stated to work with Chrome, Firefox, Safari and Internet Explorer.Read 12 Oct 2026 · squizlabs.github.io
Bookmarklet auditor
A bookmarklet provides an auditor interface for checking pages and browsing detected issues; where possible, it points to the HTML element causing the problem.Read 12 Oct 2026 · github.com
Browser extension
NoRead 21 Sep 2026 · squizlabs.github.io
Browser support
The site says its auditor bookmarklet is designed to work with Google Chrome, Firefox, Safari, and Internet Explorer.Read 12 Oct 2026 · squizlabs.github.io
Client-side operation
The script is written entirely in JavaScript and does not require server-side processing.Read 12 Oct 2026 · squizlabs.github.io
Custom rules
Developers can create custom sniffs and write their own standards.Read 12 Oct 2026 · github.com
Custom standards
Developers can extend it with custom coding standards by creating their own sniffs.Read 12 Oct 2026 · squizlabs.github.io
Included standards
The site lists WCAG 2.1 Levels A, AA and AAA, and Section 508 among its included standards.Read 12 Oct 2026 · squizlabs.github.io
Languages
The README says the auditor has English by default, plus French and Polish translations, and can be extended with custom translations.Read 12 Oct 2026 · github.com
Node.js
The README documents installing HTML_CodeSniffer as a Node.js module with npm.Read 12 Oct 2026 · github.com
Scan scope
pageRead 21 Sep 2026 · squizlabs.github.io
Self-hosting
The README describes building the auditor and moving its build directory to a web-accessible location.Read 12 Oct 2026 · github.com
Server-side use
The README says it can run server-side on HTML fragments using Node.js and a DOM environment such as JSDom.Read 12 Oct 2026 · github.com
Technology
It is a client-side script written entirely in JavaScript and requires no server-side processing.Read 12 Oct 2026 · squizlabs.github.io
Translations
The auditor supports English by default, French, and Polish; the README describes translations as very basic string translations.Read 12 Oct 2026 · github.com
Ways to run
The project README describes calling it from JavaScript, using its bookmarklet auditor, or running it on the command line with a headless browser.Read 12 Oct 2026 · github.com
WCAG version
wcag 2.1Read 21 Sep 2026 · squizlabs.github.io

Where Specifiction places it

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