WebM to MP4 Converter
Convert WebM files to MP4 instantly and privately. File Converts runs entirely in your browser, so your WebM is never uploaded to any server.
At a glance
- Where it runs
- Runs in your browser — your file is never uploaded.
- File size
- Up to 500 MB per file.
- Offline
Works offline after you have used it once: the engine downloads the first time and is kept. About 30 MB, once.
- Batch
- One file at a time.
- Cost
- Free, with no account and no daily limit.
WebM is Google's open container, built for the web and holding VP8, VP9 or AV1 video. Browsers play it natively, which is why so much web video and so many screen recordings and downloads arrive in this format. Almost nothing outside a browser does: video editors, phones' native players, messaging apps and social uploads generally want MP4.
Unlike MOV or MKV, this one is a real re-encode. VP9 and AV1 are not codecs MP4 carries in practice, so the video has to be decoded and re-encoded as H.264. That takes longer than a remux and is lossy, so work from the highest-quality WebM you have rather than one already converted once.
The result plays essentially everywhere, at the cost of a larger file: H.264 is less efficient than VP9 and considerably less efficient than AV1, so expect the MP4 to be bigger than the WebM it came from.
How to convert WebM → MP4
Drop your WebM file into the converter above — it stays on your device.
Choose MP4 as the output. File Converts picks the smartest settings automatically.
Click Convert and download your MP4 file instantly.