I use it as well and it's super good, but in addition if for some reason that site doesn't find the font you need you could use this site too — https://www.whatfontis.com/. Sometimes it can beat WhatTheFont because usually there are more alternatives (but they are not that accurate).

On the other hand WhatTheFont has a forum that is super useful if automatics doesn't work. The best font finding forum I know :)