HTML Checking for Large Sites

Rocket Validator automatically checks your pages on the W3C Validator.

CSS: “filter”: "X" is not a “filter” value.

The specified CSS filter is not a standard one, and may only work in some browsers.

Check out the Filter Effects W3C Working Draft

Related W3C validator issues

Still checking your large sites one page at a time?

Save time using our automated web checker. Let our crawler check your web pages on the W3C Validator.