Firefox Plugin - HTML Validator for HTML 5

Hello everyone,

For a long while now I’ve been using the HTML Validator plugin for Firefox (

It’s worked great. Only problem is it doesn’t seem to be updated for HTML 5 (doesn’t even recognize the DOCTYPE).

Does anyone know of a similar plugin that does have support for HTML 5?


The Total Validator add-on works but it makes use of an online tool, which means you can’t use it for your localhost/intranet tests. If you only need it for public stuff then it should be good enough until a tidy lib for HTML5 will be created.

Yeah, I saw Total Validator… but unfortunately 99% of my work is localhost/intranet nowadays, so it’s a no go for me. =p

Thanks though.