Importance of W3C standards

[Alexis]

Is there any free tool available online to check a website's compatibility to the W3C standards and it's level of accessibility?

[kev woodman]

There certainly is Ryan.

You can use bobby.watchfire.com/bobby/html/en/index.jsp to check for accessibility.

Not the nicest interface in the world but highly respected.

If you want to validate your code for standards compliance you can't do better than going straight to the horses mouth and use the validator.w3.org . And if you pass you get a lovely badge from them.

[sanderson]

I would also suggest w3, as you will find some more specific tools for your specific needs,

such as – Semantic extractor, RDF Validator, Feed Validator, P3P Validator,

XML Schema Validator, MUTAT etc. along with the Link Checker and CSS Validator.

It is kind of everything under one roof.

[Peter]

For HTML and XHTML, you can use validator.w3.org while for CSS, you can use jigsaw.w3.org/css-validator. And if you are using Firefox you can use the Tidy plugin for finding errors in your code users.skynet.be/mgueury/mozilla