CodePen - A front end web development playground.
FileProInfo - It's All About Files, Software, Online Tools - 100% Free
Pastebin.com - Pastebin.com is a website where you can store text for a certain period of time.
File-Extensions.org - Large computer file extension library with detailed explanation of each file type with links to download free or associated software programs.
Logpasta - Logpasta is a simple to use CLI-based application that allows you to paste your posts.
FileInfo.com - FileInfo is the central file extensions registry and contains a database of over 10,000 file types.