HTML Checking for Large Sites
Rocket Validator integrates the W3C Validator HTML checker into an automated web crawler.
HTML issues tagged as duplicate attribute.
Attributes in HTML elements must be unique. For example, <a id="one" id="two"> is invalid as the attribute id is repeated.
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.