Compare
MP4 vs WebM
MP4 and WebM are containers for audio and video, not single codecs. MP4 is widely used across devices and services; WebM is a Matroska-based subset associated with web delivery. Size and quality depend on the encoded streams, settings, and playback environment.
Which format should you choose?
Consider MP4 when existing delivery requirements and broad device support are priorities; consider WebM when target browsers, codecs, and the publishing pipeline have been tested.
Good fit for MP4
Web video distribution
- Publishing a video encoded to the target browser's supported profile
Good fit for WebM
Web video delivery
- Serving video encoded for a browser and platform known to accept it
Basic information
| Field | MP4 | WebM |
|---|---|---|
| Extension | .mp4 | .webm |
| MIME type | video/mp4 | video/webm |
| Common uses | Web video distribution | Web video delivery |
| How to open | Open with a compatible player or browser; if it fails, inspect actual video and audio codecs. | Open in a compatible browser or player and inspect video and audio codecs if playback fails. |
| Export or convert | For another container or codec, check whether re-encoding occurs; retain the editing master and verify resolution, frame rate, and audio. | MP4 conversion may require re-encoding; verify output quality, audio, and target playback. |
Choose by use case
Publishing a video encoded to the target browser's supported profile
Web video distribution
MP4Serving video encoded for a browser and platform known to accept it
Web video delivery
WebMKey point 1
MP4 is based on MPEG-4 Part 14; WebM is defined as a Matroska subset.
More on the differencesKey point 2
Container and codec support should be checked in target browsers, devices, and editing tools.
More on the differencesMore on the differences
Test the actual video and audio codecs on target clients and compare output size and quality under the intended settings. Keep editing masters separate from delivery exports and verify captions, audio, and synchronization.
- Both containers can hold video and audio streams.
- Their supported codecs and tooling vary across playback and editing environments.
- A container change may be possible without re-encoding, but only when the streams are compatible.
Frequently asked questions
Is WebM always smaller or better for the web?
No. Results depend on codecs, encoding settings, content, and browser support.