I received an email telling me that the SE HTML Validator Std/Pro v10.01 has been released.  The email also mentioned that you can try the online version free at

I used the tool to check the Google home page, which I recently discovered was using HTML5, but was not valid.  I received the following message:

contains errorsCSE HTML Validator Professional generated 26 error messages and 22 warning messages when checking this web page. In fact, this web page generated so many errors that HTML Validator terminated the check before it went through the entire document. These problems could damage this web page’s search engine rankings as well as cause viewing problems for visitors. It is highly recommended that any problems be corrected. Why validate?

URL: <>, Charset: ISO-8859-1, Local Time: 4:22:55 AM, Date: Wednesday, January 26, 2011

Interesting to read that the problems on Google’s home page “could damage this web page’s search engine rankings” 🙂