How to Change the Default Application For Extension Files On Mac - In some cases we need to change which application is used for a particular file extension. If you find a movie player, text editor or image viewer better, you might want to use the app for all files with the same file extension. For example, QuickTime Player is the default application to view MP4 movie files on OS X, but VLC media player can be a choice.
Follow the steps below to change your default preferences:
1. Locate the file with the extension you want to change the default.
2. Right-click on the file to see the menu, and select "Get Info". (right-click is a click with two fingers on the trackpad in the Finder).
3. A window will appear with the file information, see the section called "Open with"
|Choose Spotlight > Open With|
|Open With VLC|
You can always override the default by manually opening files in different apps with right click, and select "Open With" if the default application to open inappropriately.
To make it easier to distinguish between the file extension, you might want to also make all file extensions visible. In the Finder, select Preferences on the top menu, and click on the Advanced tab. Check the box labeled "Show all filename extensions".
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