It’s easy to assume that the files we download and install on our computers are exactly what they say they are. After all, an app with a high-quality icon and a matching correct name seems legitimate – why not? Malicious software (and malware developers) thrive under these assumptions, as the goal is to open these malware without a doubt. Fortunately, there is an easy way to know the type of any particular application, program, or file on your Mac or PC; it is simply not enabled by default.
There are built-in settings in both macOS and Windows that will reveal the file extension of any file on your computer next to its name. Instead of Final Cut Pro, you will see Final Cut Pro.app: instead of Elden Ring, you will see Elden Ring.exe. This appears for all files on your computer, which may not work well for some users. Not revealing file types is an aesthetic choice, and I understand that: it’s a much cleaner look to see all your apps and files on your computer without those three- or four-letter extensions at the end. I will talk about a way to show the true extension of a file at will for those who prefer to keep things tidy.
However, keeping file extensions on all the time can be a life-saving (computationally speaking) endeavor. Malicious software in Windows is often written as an executable file, a type of basic file that tells the computer to run a task or series of tasks. This file extension appears as .exe, but you don’t know it if you don’t have the file extension view enabled. Malware developers know this and write their malware accordingly. A malicious software file may appear on your computer as thedarkknight.mov, but it reveals its full name and you will find that it is actually called thedarkknight.mov.exe. Not so innocent.
This is not to say that all .exe file types are malicious. Far from it: .exe is a common and legitimate file type that is used all the time in Windows. You may have noticed in my example a few paragraphs earlier that a game like Elden Ring will appear as an .exe file, and that’s to be expected. The point is not to be afraid of all the .exe you find: rather, it is to be able to identify when a file appears that should not be a .exe. Remember: If a file or application that you have downloaded from the Internet or as an attachment to a message appears to be incomplete, do so with caution and avoid opening it.
This setting can also be useful in other ways: Sometimes it’s important to know what specific file type you’re working with, especially when it comes to compatibility. There are many different types of image file types, for example, and you won’t be able to know which one you’re in front of just knowing you have a photo. This image could be a .jpeg, .pdf or .heif: you will know instantly if your computer tells you to.
How to display file extensions in Windows
Fortunately, it’s not difficult to turn on settings to see file extensions in both Windows 10 and Windows 11. For Windows 10, open File Explorer, choose “Show”, and then click the tab that is next to “File Name Extensions”. For Windows 11, open File Explorer, choose “View,” then “Show,” and then choose “File Name Extensions” from the list.
You don’t need to show the extensions of all the files on your computer to stay safe, but if you prefer to keep things clean and inspect the files on a case-by-case basis, here’s how: Right-click the file. , choose “Properties” and then check its extension next to “Type”.
How to Display File Extensions on Mac
Although you won’t find .exe files on your Mac (at least you can’t run them, anyway), it can still be useful to show file extensions. After all, the same philosophies apply: you don’t want to open an app or file with a radically different extension than you expect, and it can be helpful to know exactly what type of file you’re working with right now.
To display file extensions in macOS, open Finder, and then press Command + to open Preferences (alternatively, choose Finder from the menu bar, then select “Preferences”). In the Preferences window, choose the Advanced tab, then check the box next to “Show all file name extensions.”
If you prefer to inspect a file extension, instead of displaying all file extensions by default, you can right-click on the file and choose “Get Info.” The actual file extension will appear next to “Type”.