This is a node.js and Python front-end to the Mozilla Labs' HTML Validator Web Service, located at https://validator.mozillalabs.com/. It was setup in order to be used in the build system of various Mozilla projects, without spamming the main validator (i.e., http://validator.nu) --see https://bugzilla.mozilla.org/show_bug.cgi?id=763804. You can read more about the validator at https://validator.mozillalabs.com/.
You can and should use it in your own Mozilla project's build system in order to automatically check your HTML for errors.
html5-lint module can be installed via npm:
$ npm install html5-lint
Once installed, it can be used like so:
var fs =html5Lint = ;fs;
html5check.py -h file.html
You can test the parser with the supplied files:
$ ./html5check.py -h good.htmlThe document is valid HTML5 + ARIA + SVG 1.1 + MathML 2.0 (subject to the utter previewness of this service).
$ ./html5check.py bad.htmlError: Start tag seen without seeing a doctype first. Expected