MP4 vs WebM

MP4 with H.264 is the compatibility king. WebM with VP9/AV1 is the open-web alternative. Neither name is a codec; inspect the payload.

If you can only ship one file, H.264 MP4 still reaches the most players. If you control recent browsers, WebM or AV1 can save bytes. ConvertPass can re-encode a short clip to whichever of those this browser can encode.

Typical codecs

MP4. H.264, H.265, AAC.

WebM. VP8, VP9, AV1, Opus.

Browsers

MP4. H.264 is the safest.

WebM. Strong in Chromium; test Safari for your actual encode.

Editors

MP4. Every NLE exports it.

WebM. Available, not always the default.

Licensing story

MP4. H.264/HEVC have patent histories.

WebM. The royalty pitch is part of WebM’s original appeal.

Topic	MP4	WebM
Typical codecs	H.264, H.265, AAC.	VP8, VP9, AV1, Opus.
Browsers	H.264 is the safest.	Strong in Chromium; test Safari for your actual encode.
Editors	Every NLE exports it.	Available, not always the default.
Licensing story	H.264/HEVC have patent histories.	The royalty pitch is part of WebM’s original appeal.

Related tools

Video compressor
Auto-compress a short clip locally to MP4 or WebM, using this browser’s encoder.
Video file inspector
Read duration and resolution from a video without uploading it.
Social video export settings
Use researched starting points for social exports, with the re-encode caveat attached.

Related formats

Last reviewed 16 August 2026.