How to open a .mp4 file: without installing anything

How to open a .mp4 file

A .mp4 is a MP4 file: H.264 video and AAC audio. Plays on absolutely everything. VLC (free, everything), Windows Media Player, QuickTime, IINA open it. Or drop it below: it opens and converts in your browser, nothing to install.

Drop files here or click to chooseSeveral files at once are fine.

🔒 Nothing is uploaded. Check the Network tab of your browser: it stays empty.

Three ways to open it

Drop the .mp4 file above: it opens and converts right here, nothing to install.
For a desktop app: VLC (free, everything), Windows Media Player, QuickTime, IINA.
If it still will not open, convert it to WebM, that is what most people are really after.

Convert a .mp4

MP4 → WebM MP4 → MKV MP4 → MOV MP4 → AVI MP4 → GIF MP4 → MP3 MP4 → WAV MP4 → M4A

Questions

What program opens a .mp4 file?

VLC (free, everything), Windows Media Player, QuickTime, IINA. Or drop it here, without installing anything.

Why won't my .mp4 open?

Either the viewer does not know MP4 (h.264 video and aac audio. plays on absolutely everything.), or the file is damaged or misnamed. Converting to WebM fixes the first case.

Is it safe to open a .mp4 here?

Yes: the file is read in your browser and never leaves your device.