Minify your HTML by removing all the unnecessary characters.
Minify your JS by removing all the unnecessary characters.
Extract email addresses from any kind of text content.
Convert markdown snippets to raw HTML code.
Take an IP and try to look for the domain/host associated with it.
Convert forum type bbcode snippets to raw HTML code.
Validate JSON content and make it looks good.
Get all the HTTP headers that an URL returns for a typical GET request.