On Mac (OS X Mavericks or OS X Mountain Lion), all file extensions will be hidden by default; however, sometimes it’s hard to recognize what are they. It’s easy to show all file extensions on Mac, please follow these simple steps.
Show File Extensions On Mac
1. Go to Finder and then choose Preferences
Mac Finder Preferences
2. Go to Advanced tab then check on box ‘Show All filename extensions’
Mac – Show All Filename Extensions
