Open Validator

Open Validator is a tool to help all you web developers out there check whether your webpages look good in all browsers (or at least the most popular ones) and support all the desired languages.

Using this program is as easy as typing the address of a webpage or selecting the filepath for a page from your local drive (if you have it there). That done, just confirm a series of preview options and, after around a minute, you can start checking out the content of the page in question.

In the program's main window you have a permanent navigable preview of the webpage under analysis, on one side a list of detected errors and anomalies, and your HTML code at the bottom.

Open Validator is a super useful tool for website developers who in general want to ensure their output looks good and works properly.