Firefox Extension for CSE HTML Validator

information item Unfortunately this extension has problems with current versions of Firefox and CSE HTML Validator and no longer appears to be under development. Consider using the integrated web browser in CSE HTML Validator instead. It allows you to browse the web while validating the HTML source.
Firefox 4 support

The HTML Validator by Marc Gueury for Firefox extension (new window) supports recent versions of CSE HTML Validator (v10.02 or greater, any edition). In the options, choose CSE HTML Validator for the Algorithm (highlighted in the screen shot). View the page source to see the validation results.

Select CSE HTML Validator for the Algorithm in the Options dialog

Important