MP4 vs WebM vs MOV: which video format should you use?
The extension on the end of your file is only the box, not the quality of what is inside it — the codec, the bitrate, the size and the frame rate all matter more. Still, picking the right box avoids an entire category of upload failures and playback problems, and it takes about six minutes to know which one you want.
MP4: the one that always plays
MP4 holding H.264 video and AAC audio is the most dependable file you can hand to anyone. It plays in browsers, on phones, in presentation software and on every large social platform, and it supports fast-start metadata so playback can begin before the whole file has arrived.
What MP4 cannot do is carry a transparent background in any way the web reliably understands. If your subject needs to float over something else, that is a job for WebM.
WebM: light, and it can be see-through
WebM usually contains VP9 or AV1 video with Opus audio. It plays efficiently in browsers, and VP9 can carry a real alpha channel — which is exactly what you need for a subject whose background you have removed.
Outside the browser it is a gamble. Some mobile apps and older editors refuse a WebM even when the same device plays an MP4 without complaint, so keep it for the web and for compositing.
MOV: great to shoot, awkward to send
MOV is what cameras and Apple software like to produce. It happily holds edit-friendly codecs and high-quality footage, which is exactly why the files are enormous and why upload forms so often turn them down.
Convert MOV to MP4 when you are making the copy you send to someone. Keep the MOV when it is your camera master or holds a codec you will want again for colour work.
No converter can un-ruin a file
Changing the container or the codec can fix compatibility and bring the size down, but nothing can put back detail that an earlier compression already threw away. Every extra round trip through a lossy format costs you a little more. Work from the best copy you have and make one delivery export at the end, not five in a row.
- ✓Sending it to someone or posting it? MP4.
- ✓Needs to be light on the web, or see-through? WebM.
- ✓Came off a camera and you might re-grade it? Keep the MOV.