MP4 vs WebM: Which Video Format Should You Use?
Updated November 5, 2026
Use MP4 for sharing and uploading, because nearly every device, app and website can play it. Use WebM for videos on your own website when small files matter. WebM's newer codecs can be smaller, but it isn't as widely supported outside browsers.
What's actually different
Both are containers. MP4 usually holds H.264 video with AAC audio. WebM holds VP9 or AV1 video with Opus audio. Those newer codecs are more efficient, while H.264 has the widest hardware support.
Which should you use?
Pick by where the video is going.
- 1Sending to people, or uploading to social apps: MP4.
- 2Editing in most video apps: MP4.
- 3A web page where every megabyte counts: WebM, with MP4 as a fallback.
Convert when you need to
Browser screen recorders often save WebM. If an app won't open one, converting to MP4 fixes it, though the file may come out larger.