CSE HTML Validator Lite is a fast, easy to use, and FREE (for personal and educational use) HTML development tool for Microsoft Windows that helps you create problem-free HTML and XHTML documents. It's also a great learning tool.
CSE HTML Validator: This free application is very useful for checking out and validate all the web page scripts or the selected part of it. The application scans the web page HTML code checking invalid tags, invalid tags attributes or values, misspelled sentences and invalid characters. It alse looks for quotation marks that might be missing or mismatched, missing tags, all over the HTML code.
CSE HTML Validator Pro: This application is very useful for checking out and for validating all the web page scripts (or a selected part of it). The application scans the web page HTML code checking invalid tags, invalid tags attributes or values, misspelled sentences and invalid characters. It also looks for quotation marks that might be missing or mismatched, missing tags, over the HTML code.