The file might be corrupted, or you may be missing a specific "codec" (the software used to compress the video). Try opening it with VLC Media Player .

MP4s are generally compressed, but high-definition videos can still be large. You can use tools like Handbrake to compress the file further for easier sharing.

The (MPEG-4 Part 14) extension indicates a digital multimedia container format most commonly used to store video and audio. It is a versatile format that can also include subtitles and still images. How to Open It You can play this file using most standard media players:

: Right-click the file, select "Open with," and choose Windows Media Player or the Movies & TV app. Mac : Use QuickTime Player or Apple TV .