Show all filename extensions

It’s easy to show and hide file extensions on the Mac. In fact, you can reveal file extensions for individual files, and show or hide file extensions globally.

By default, OS X ships with file extensions for popular filetypes hidden. So image files with the .png extension will omit the .png at the end of the filename, and apps will likewise discard the .app extension.

There are several ways to manage filename extensions in OS X. In this video, I’ll show you a couple of effective ways to get you started.

Managing app extensions globally

The most popular method for managing app extensions [read: unhiding them] is to do so globally. This is accomplished via Finder’s preferences.

Step 1: Open Finder

Step 2: Click Finder in the menu bar → Preferences

Step 3: Click the Advanced tab

Step 4: Check Show all filename extensions

You should now see all of the files on your Mac sport extensions.

Individually unhide filename extensions

Step 1: Right click on the file → Get Info

Step 2: Click the Name & Extension disclosure triangle (if collapsed) and uncheck Hide extension

Hide extension individual file

The individual file setting only appears to work one way, meaning that it will only unhide an extension when extensions are hidden globally, but will not hide an extension will extensions are unhidden globally using the initial Finder method above.

As mentioned, there are other ways to manage extensions that we may discuss in a future post, but this should be enough to get you started, especially if this is the first time you’ve encountered such a question.

How do you use your Mac? Do you keep extensions hidden for know file types, or do you keep them all enabled? Sound off down below in the comments section.

  • asdf4512

    Wow, there is even a video about this! We would never find out for ourselves, for sure.

  • Domodo

    But how to hide all extensions in Mac OS?

    • But why would you want to? I don’t think it’s as prevalent in OS X as it is in Windows but by hiding file extensions you could be tricked into opening thinking it’s a zip file when in actuality it’s an executable…

      • Domodo

        I’m not a novice Mac OS user, so I’m pretty sure I’d recognize a fishy file. What buggs me are some .jpg and .pdf extensions that show up only on some files and won’t go away.