Change Default Application for File Extensions on a Mac


Macintosh operating systems


A particular file extension is opening in a different application than what you want to use. For example, a CSV file may be opening in the Numbers app instead of Excel. Or a MP4 video file may use QuickTime Player, but you would prefer to use VLC.


  1. Find a file with an extension you want to change the defaults to (example: a .csv file)
  2. Right-click on the file to see a menu, and select “Get Info” (right click is a two-finger click on a trackpad)
  3. A window appears with the file’s information, see the section called “Open with”
  4. It will display the current application used for this file, use the drop-down box to select your new application
    1. If you do not see your new application in the drop-down box, use the “Other” selection to browse for it
  5. Click on the “Change All” button to apply the change to all files ending with the same file extension

Additional Information

Need additional information or assistance? Contact the ITS Service Center.


Article ID: 7010
Fri 1/14/22 11:44 AM
Mon 2/20/23 5:50 PM