Determining file type with TrID

trid_icon Type of file is usually indicated by extension in the end. Unfortunately it isn’t set in stone and there are situations when you stare at file lost on what to do with it. I have been given bunch of files without extension and asked to “Print it… Why should I know that?” more than once. :)

One of the ways to handle that is looking at file content. Not very human-friendly in case of binary files (that’s why I stick to plain text). TrID is an utility which does that without much trouble.


TrID uses big number of user-submitted definitions generated by analysis of different files to make educated guess about type. Sometimes it gives clear result, sometimes there are few possible variations.


App comes in three different forms:

  1. Command line utility.


  2. Graphical interface version (TrIDNet).


  3. Online service.



While effective as CLI utility as graphical one TrIDNet suffers from different definitions packaging (few thousands of xml files) and requiring .NET Framework (making it less portable than it could be).

TrID http://mark0.net/soft-trid-e.html

TrIDNet http://mark0.net/soft-tridnet-e.html

Online TrID http://mark0.net/onlinetrid.aspx

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  • Ky #

    Nice find!
  • Rarst #

    Thanks. :) It's (again) one of those tools that are rarely needed but still very useful.
  • Adrian #

    Some scanners save files without extensions, so it's great to have such a tool to check the file extension. I've already reviewed it! adrian
  • Rarst #

    @Adrian Yeah, staring at file without extension can indeed be very confusing experience, I know it first-hand. :)