How to view file extensions on your computer

What is a File Extension?

File extensions are the part of a file which associates the file with an application. Let’s say you have a PDF document, it would be usually a name followed by a “.pdf”: for example “myfile.pdf”. When you rename a file, you are only renaming the first part before the “.” part. While most people refer to the last part of a filename as file extensions, others refer to it as file suffix, file format or even file-type. It varies from person to person however all of these nomenclatures are correct.

How to view File Extensions?

Sometimes it is useful to view the file extension of a particular file for various reasons, like for example when you try to open a particular file and your computer tells you that you don’t have the needed application to open it. In this case you have to check the file extension in order to search the Internet for the application that opens a file with that particular file extension. Now for the interesting part: how to view the file extension. Assuming you have a Windows operating system (it doesn’t matter which version as the principle is still the same):

1. Go to My Computer
2. In the Menu Bar click Tools -> Folder Options
3. Select the View tab in the Window that pops up
4. See that ‘Hide file extensions for known types’ is unchecked

That’s all folks. Now you can see all the file extensions to your heart’s content. If you need a fix of some really cool libraries to search file extensions and get extensive information on what types of applications are associated with them try these websites.

File Extension Library

Dot What

Note: It is very important to not change file extensions unless you have a very good reason. Changing the extension can (and usually does) make the file unusable.