Click to upload or drop a WebM video here
Converted in your browser — never uploaded. You can switch tabs while it runs.About this converter
This free WebM to MP4 converter turns a WebM video into an MP4 (H.264 video + AAC audio) that plays almost everywhere — phones, editors, social media and players that don't support WebM.
It runs a real video engine entirely in your browser, so your file is never uploaded to a server. Because the work happens in a background worker, you can switch to other tabs or apps while it converts — just keep this tab open.
Good to know
- The conversion runs in the background — switch tabs freely, just keep this tab open
- The first run downloads a one-time ~30 MB engine (then it's cached); a connection is needed once
- It re-encodes the video (WebM/VP8/VP9 → MP4/H.264), so it's best for short clips and can take a little while
- Everything is processed on your device — nothing is uploaded
How to use it
- Upload your WebM — click the upload area or drag and drop a .webm file
- Convert — click Convert to MP4; you can switch tabs while it works
- Download — when it's done, preview it and save your MP4
Credits
Conversion is powered by ffmpeg.wasm (FFmpeg and x264, licensed under GPL-2.0).