Firefox

  Total Validator Firefox Extension is really a awesome tool and is a hybrid(much advanced version of theW3C validator) and its really easy to use.Once you have downloaded and installed the Total Validator Plugin for Firefox ,all you need to do is navigate to the Webpage that you want to Validate and Click on the TV icon that you see in the Firefox status bar. To make things even more simple ,you can even make a right click on the Webpage and select the TV icon again and select you method of validation. Download Firefox Total Validator Plugin