HTML_CodeSniffer is a client-side JavaScript that checks a HTML document or source code, and detects violations of a defined coding standard.

It can be used in two ways. Called directly in JavaScript source, HTML_CodeSniffer will provide a list of known and potential violations to the calling script. It also comes with a pop-up auditor interface, accessible via a bookmarklet, letting you browse through messages emitted from one of the defined standards. Where possible, the auditor also points you to the HTML element causing the problem.

HTML_CodeSniffer is released under a BSD-style licence. For more information, please see the file "licence.txt".

HTML_CodeSniffer comes with standards and sniffs that cover the three conformance levels of the W3C Web Content Accessibility Guidelines (WCAG) 2.0, and the U.S. Section 508 legislation.

To report any issues with using HTML_CodeSniffer, please use the HTML_CodeSniffer Issue Tracker.

Contributions to the HTML_CodeSniffer code base are also welcome: please create a fork of the main repository, then submit your modified code through a Pull Request for review. A Pull Request also automatically creates an issue in the Issue Tracker, so if you have code to contribute, you do not need to do both.

More information on HTML_CodeSniffer can be found on its GitHub site, http://squizlabs.github.io/HTML_CodeSniffer/. This site provides:

• Information on the tests performed (and messages emitted) by HTML_CodeSniffer's standards, organised by conformance level and Success Criterion;
• A source test area that allows you to try out HTML_CodeSniffer with your own HTML source code; and
• A link to the HTML_CodeSniffer bookmarklet, letting you check other pages using the pop-up auditor interface.