WEBM to MP4 converter
Convert WEBM to MP4 in seconds, free and unlimited. No upload, no sign-up, no watermark: your video never leaves your device.
Last updated
Quick answer: To convert WEBM to MP4, add the WEBM file to the iHateFiles WEBM to MP4 converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. H.264 in an MP4 is the one combination that plays on essentially every device made this century.
Where WEBM files come from
WEBM is what browsers, screen recorders and many websites produce, because it is open and efficient. It plays in Chrome and Firefox, and often not in phone galleries, editing apps or PowerPoint.
As an MP4 it works in all of those. WEBM can be a little smaller for the same quality, so do not expect the file to shrink; the gain here is that it opens.
Should you convert WEBM to MP4?
Yes, if the WEBM will not play where you need it. MP4 with H.264 plays on essentially everything, which is why nearly every other video format is converted to it.
The picture is re-encoded
A WEBM usually holds VP8, VP9 or AV1 video with Vorbis or Opus sound. This writes H.264 video with AAC sound into the MP4. Both sides are compressed with loss, so this is a second generation: leave the quality at its default or higher, because the encoder is working from WEBM artefacts rather than the original.
Where the MP4 will play
MP4 plays on every phone, laptop, TV, browser and messaging app.
WEBM and MP4 side by side
| WEBM | MP4 | |
|---|---|---|
| Inside the file | VP8, VP9 or AV1 video with Vorbis or Opus sound | H.264 video with AAC sound |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| Plays on | every modern browser and Android, but not QuickTime or older iPhones | every phone, laptop, TV, browser and messaging app |
| Here | Read and write | Read and write |
What usually goes wrong
About the WEBM. A browser screen recording is usually a WEBM with a broken duration, so players show it as zero seconds or refuse to seek. Converting it to MP4 rewrites the header and fixes the seeking.
About the MP4. Two MP4 files can behave completely differently depending on the codecs inside. A file that will not play is usually an unusual codec in an ordinary container, not a broken file.
How to convert WEBM to MP4
- Add your WEBM file. It is read from your disk and stays there.
- Check the settings. The output format is already set to MP4.
- Press convert and the MP4 file is saved back to your device.
MP4 converter: everything that converts to MP4
Questions
How do I convert WEBM to MP4?
Open this page, add your WEBM file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this WEBM to MP4 converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to MP4 lose quality?
MP4 is a lossy format, so some detail is discarded. The quality control on this page decides how much. The default is set high enough that most people cannot see the difference.
Can I convert several WEBM files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.