Webmasters have to watch that their web pages don’t have HTML mistakes as this will help search engines to better index the document and assist in the content interpretation.
For checking the code’s correctness we advise you to use the following tools:
- HTML-validator from W3C
- CSS-validator (checks CSS-code for correspondence to W3C requirements)
- Feed-validator (checks RSS, Atom and KML feeds)
We also recommend the document’s availability for correspondence to Section 508 requirements. You can do this at
http://www.contentquality.com/