posted on June 8, 2009 by Varun Kashyap

Ever get stuck with any unrecognizable file extensions? If you get a lot of attachments in the mail, you’ll know what I am talking about. It is amazing how messed up things can get if one of your friends or colleagues enters a wrong file extension.

So, what do you do? How can you identify unknown files? Spend the next 10 minutes trying to open it in Word, PowerPoint, Open Office or maybe it is a PDF? Or perhaps you Google for some information. What if the extension is wrong?

TrID is a nice little utility to have on your computer for situations like this. Linux users have something similar in the “file” command. TrID identifies file types based on their signatures. What distinguishes TrID is the fact that it uses database of definitions to identify file types. This database is ever expanding (somewhat like definitions for Antivirus programs) and allows TrID to identify a wider range of file types.

You can use TrID in 3 flavors. The TrID – File Identifier is inherently a command line utility. You can pass the file to be identified as an argument and use the various switches to view additional information about the file in question. You don’t need to worry about typing long paths and filenames. You can use the -v switch for additional information, -w to wait for key press after showing results and -d to specify a different definitions package.

TrIDNet is the GUI version of TrID. Browse to the file you want to analyze and allow TrIDNet to enlighten you! Double-clicking on an item would show extra information about it.

You can also use TrID Online. Just visit here, upload the file you want to identify, hit Analyze and wait for the results to show up. You can also run through the various file extension definitions if you just want to look up a particular file extension and what it does.

TrID is a great utility to help you identify unknown filetypes with ease. You can then search the web if you are unsure of the software you should use to open the identified file. Try Openwith for the same result.

If you encounter a file type that is not (or wrongly) identified by TrID, you can help create definitions using TrIDScan and other TrID users will be able to benefit from your created definitions.

Do you know of any similar utilities that can be used to identify unknown files? Which sites do you refer for information on file extensions? Share with us in the comments.