Convert WEBM to MP4
WEBM is made for browsers, and almost nothing else takes it: not Premiere, not Resolve, not PowerPoint, not an iPhone. Convert it to H.264 in an MP4 and it drops straight into any of them.
- Processed on your device
- No upload, no waiting
- No signup, no watermark
How it works
Add your WEBM
Drop the file. VP8, VP9 or AV1 video and Opus or Vorbis sound are all read here.
Let it convert
The picture is re-encoded as H.264 at the original size and frame rate, and the sound as AAC.
Download the MP4
Ready for an editor, a phone, a slide deck or a client.
Frequently asked questions
Why must WEBM be re-encoded?
Because its video is VP8, VP9 or AV1, and an MP4 that programs actually accept holds H.264. The picture is decoded and re-encoded at high quality — a screen recording or animation comes through looking the same.
Is my file uploaded?
No. Your browser already decodes WEBM to play it, and it encodes H.264 for video calls; both are used here directly, so the file stays on your device.
The file got bigger. Why?
VP9 is more efficient than H.264 at the same quality, so matching the quality costs more bits. That is the price of a format everything can open. Use Compress Video afterwards if the size matters.
What about the transparency in my WEBM?
MP4 with H.264 has no alpha channel, so transparent areas become black. For transparency, keep the WEBM, or export a GIF with Video to GIF.
Does it work for long screen recordings?
Yes. Encoding runs in a background thread with hardware help, and the output is streamed to storage rather than held in memory, so an hour-long recording is no problem.
Will the sound stay in sync?
Yes. Both tracks are rebuilt on one clock, which also repairs WEBM recordings that start with a gap — a common quirk of browser-recorded video.
Good to know: Alpha transparency is lost, because H.264 in MP4 cannot carry it. AV1 video is decoded only where the browser can decode AV1 — recent Chrome, Edge and Firefox can.