Will it lose quality?

Any re-encode loses a little. Choose High quality and Keep original resolution to keep it to a minimum.

Can I convert MP4 back to WebM?

Yes. The same video panel writes WebM with VP9 or VP8.

Does it upload my recording?

No. Screen recordings often show things you'd rather not share; this one never leaves your browser.

Convert WebM to MP4

Re-encode a WebM (VP8 or VP9) into an H.264 MP4 that editors and older devices accept. Nothing uploaded.

WebM is what screen recorders, browser downloads and a lot of web video produce. It plays almost everywhere on the web, but video editors, presentation software and older phones often refuse it. Re-encoding to H.264 in an MP4 fixes that.

This is a real re-encode, not a container swap: most MP4 players expect H.264 video, not WebM's VP8 or VP9, so the picture is encoded again. Pick a quality level — high, medium, low or tiny — and that sets the bitrate, which is what decides the file size.

A subtle trap this avoids: asking a browser for a plain "MP4" can quietly give you VP9 video inside an MP4 file, which many players won't open. The converter names H.264 explicitly, so the result is the MP4 people actually mean.

Worth knowing. Conversion runs at normal playback speed, so a five-minute recording takes about five minutes. The audio track is encoded as Opus, because browsers don't ship an AAC encoder; choose Remove audio if the clip is silent anyway.

Questions

Will it lose quality?: Any re-encode loses a little. Choose High quality and Keep original resolution to keep it to a minimum.
Can I convert MP4 back to WebM?: Yes. The same video panel writes WebM with VP9 or VP8.
Does it upload my recording?: No. Screen recordings often show things you'd rather not share; this one never leaves your browser.

Everything the converter reads and writes →

Runs entirely in your browser. The file is never uploaded, so there is nothing for us to store, log or lose. No account, no watermark, no size paywall.