Do you want to open MP4 or AVI files with VLC instead of QuickTime? You just need to change the default application they are associated with .
When you double-click a file, your Mac opens it with the default OS X application for the corresponding file type. But we don’t always want that to happen.
A classic example: you want to listen to an AVI or MP4 video file only once, so you don’t want to open it with iTunes, which would save it to your library. The ideal then is to watch it with a more dynamic player, such as QuickTime.
As a solution, you can press the right mouse button on the file in question, go to the Open with option and select the desired application.
However, there is also a way to tell your Mac that you still want to open certain types of files with a certain application. This way, double-clicking on the file will suffice.
As an example, in this article we are going to configure OS X to always open AVI files with VLC but the same procedure is valid for any type of file.
1. Open the file information window
Right click on an AVI format file. From the context menu, select the Get Info option . The menu name may change slightly depending on the version of the operating system you are using.
The file information window will then open.
2. Set the default application
Go to the Open with section and from the drop-down menu choose VLC Player.
3. Apply the selected program to all similar files
Press the Change All… button . Your Mac will display a message asking for your confirmation so that, from then on, all files of this type (in our case, AVI) are opened with the application selected in the drop-down menu (in our case, VLC).