HTML Escape is a tool for HTML escaping process. When escaping, it replaces special HTML characters with their HTML equivalents (entities).
For example, if you need to post a piece of HTML/JavaScript code in your article/blog post/any other HTML document, you need to escape it to make browsers don't treat it as HTML. It means that you need to replace all HTML reserved characters (<, >, &, ") into their entities (<, >, &, ", accordingly). This tool simplifies such a task.