Convert WebM to MP4
Convert WebM to MP4 for free, right here in your browser. The video never leaves your device, however large it is.
- Free
- Runs on your device
- No account
- No limits
One file at a time. The video is converted on your own device, so nothing is uploaded and there's no size limit beyond what your browser can hold.
How to convert WebM to MP4
- Drop your WebM file in the box above, or click the box to pick one.
- The first video also fetches the conversion engine, about 7MB, which your browser then keeps. After that it starts straight away.
- Watch the progress bar. Your own machine is doing the work, so leave the tab open until it finishes, then download.
Why convert WebM to MP4?
WebM comes out of screen recorders and browser downloads, and video editors are the usual thing to refuse it. MP4 is what they all expect.
This one takes real time. MP4 cannot hold what a WebM normally contains, so every frame has to be decoded and encoded again. Expect roughly as long as the video lasts, and more on a long or high resolution file.
About the two formats
WebM: Built for the web and free of licensing. Smaller files, but slower to produce.
MP4: The format everything plays. H.264 video inside an MP4 container is the safest thing to hand anyone.
A video file is a box with codecs inside it, and the box and its contents are separate things. Moving a video into a different box is bookkeeping, and takes a second. Changing the codec means rebuilding every frame, and takes about as long as the video runs. That's the whole difference between the quick conversions here and the slow ones.
Common questions
Is the WebM to MP4 converter free?
Yes, properly free. No paid tier, no trial, no watermark on the result and nothing to sign up for. Put as many files through it as you like, as often as you like.
Are my files uploaded to a server?
No. The WebM to MP4 converter runs inside your browser, on your own machine, so your files never go anywhere. Big ones are fine too, up to whatever your browser can hold.
Does converting WebM to MP4 lose quality?
A little, because MP4 can't hold what a WebM contains, so the video has to be decoded and encoded again. It's set to a quality where the difference is hard to see on normal footage. What you should not do is convert the same file back and forth repeatedly, since each pass costs a little more.
How long will converting a WebM to MP4 take?
Roughly as long as the video itself, and longer for high resolution footage, because every frame is being rebuilt. A one minute clip is a minute or two of waiting. There's a progress bar rather than a guess, and the tab has to stay open, since your own machine is doing the work.
Is there a limit on the size of the video?
Not one we set, but there's a practical one. The whole file is held in your browser's memory while it works, so very large files can run a tab out of room, and a phone gives up sooner than a computer. Files up to a few hundred megabytes are comfortable on an ordinary machine.