Simpletidy is a very useful yet very small program that can be used to clean up your HTML code. HTML code is the language that forms Internet webpages, and it is required to be clean so that pages would be smaller in size and loaded faster for users with slow connections. In addition, the pages will be favorable to search engines and will be more human and machine readable.
The program adds the correct Doctype to your HTML document. It also fixes incorrect tags, add missing end tags, removes duplicated spaces and lines, adds missing quotes and more. After processing, your resulting code will be fully compatible with XHTML 1.0.
A very interesting feature that I found is the ability to process multiple HTML files at once. It can process sub folders (if selected), and make backups of the original files. Best of all, it's free to be used for non-commercial purposes.
The program has an internal code editor that colors the code's syntax so you could evaluate your HTML code and detect syntax errors easily. The code editor has a simple function to find and replace text within your code. Using the preview function, you can preview your HTML code before and after processing in your default browser.