Validation

Validation is a way to make sure that your code is compliant with the current HTML specifications. This means you can check to make sure that you didn't accidentally use proprietary tags that would only work on your particular browser. There are many HTML validation sites on the Web, such as Bobby, which will analyze single web pages for their accessibility to people with disabilities, Weblint, one of the first validators, and the World Wide Web Consortium's rigorous validator, which provides validation for HTML 4.0.