Show File Name Extensions in Mac OS X
File extensions (like .jpg, .txt, .pdf, etc) make it easy to see what a specific file type format is, but as many Mac users notice, those file extensions are hidden by default in Mac OS X. While hiding the format suffix makes for a cleaner user experience and is fine for many users, it can be frustrating if you’d rather know instantly what file format type a file is just by looking at the name, and for many power users it’s one of the first things changed when setting up a Mac.
As we’ll demonstrate, OS X offers two choices for displaying file format extensions after file names: You can either set all extensions to be displayed for every file in Finder through a universal setting, or you can set extensions to be shown on a per file basis with the help of the Get Info command. For either choice, the file format type will be shown as part of the file name, changing something like “File” to display as “File.txt”.
How to Show or Hide All File Extensions
- From the Mac OS X Desktop, pull down the “Finder” menu and choose “Finder Preferences”
- Click on the “Advanced” tab (gear icon)
- Check the box next to “Show all filename extensions”
Changes are immediate and you’ll find the extensions visible instantly across the Finder for all files and file format types, the screen shot below demonstrates this:
Selectively Show or Hide Filename Format Extensions
If you’d rather not see them all, or if you want to hide some and show others, you can also show (or hide) file extensions on a per file basis.
- Select a file and hit Command+i to bring up the “Get Info” window
- Click the arrow alongside “Name & Extension:” to expand the options, and check or uncheck “Hide extension”
For many users, not seeing filename extensions is probably fine, but I often set custom file associations, and knowing the extension will let you know what app is going to open with each file without looking at the “Open With” menu to be certain.