
But why is that so? The note below the message explains the reason: The file isn't compatible with Quicktime Player. You may once get this message while trying to open your MP4 video: the document "file.mp4" could not be opened. It streams MP4 files smoothly on Mac models, and you can also use it for other multimedia formats like M4V, MOV, MP3, and WAV files.ĭespite being an MP4 player for Mac, QuickTime doesn't play all MP4 files. QuickTime is the default media player released by Apple and bundled with macOS. Mac users may be confused when they can't open MP4 by Quicktime Player.įor Mac users, when you want to play a video, the first media player/streaming platform that comes to mind is the QuickTime Player.

You can use Quicktime Player alternatives like Elmedia Player, VLC media player, 5KPlayer, and other MP4 players for Mac to play those videos.

