Choose a file to convert. It's processed locally — never uploaded. Tip: add several files to convert them all at once.
{ } How it works
What it is
Convert an MP4 video to WebM (VP9/Opus). Slower, but smaller and open.
How it works
MP4 to WebM works on the file you upload. Select Process ▸ and it runs entirely in your browser — nothing is uploaded to a server — then shows the result in the Output panel.
Input
- Video file — upload a file (video/*); it is read locally in your browser
Output
WEBM text — copy or download it from the Output panel.
{ } FAQ
Is my data uploaded to a server?
No. Everything runs locally in your browser — your files never leave your device.
Can I process more than one file at once?
Yes — add several files and they’re all processed and downloaded together as a ZIP.
Is this tool free?
Yes — it’s completely free and needs no sign-up.