HTML Validator

If you are working with webs, perhaps you have heard about XHTML from W3C. Yes, it is a new specification that compliant with XML specification that should be used rather than HTML. But how can you make a transition from HTML to XHTML? You can use HTML Tidy to correct wrong markup locations. It is a great tool.

Now, there is another Firefox's extension called HTML Validator (based on Tidy) that works on local pages, so you can update your pages so that it will be XHTML compliant. Next, you can upload it to your web server. The only thing you have to do is click the View Source menu, and the Tidy will show your errors or warnings on your pages that you open.