WEBM to MP4 Converter
WEBM in.
MP4 out.
+
Drop a video here
or choose a file · MP4, MOV, WebM, MKV · processed on your device
To convert WEBM to MP4, drop your WEBM video in, check that MP4 is selected and press Convert to MP4. When the codecs allow it the video is copied without re-encoding, so it is fast and lossless; otherwise it's re-encoded on your device.
How to convert WEBM to MP4
- Drop a WEBM file into the box above.
- Make sure MP4 is selected (Resolution "Original" keeps full quality).
- Press Convert to MP4 — the file downloads when it's ready.
Video formats at a glance
| Format | Usual codecs | Plays on | Typical use |
|---|---|---|---|
| MP4 | H.264 / HEVC + AAC | Everything — phones, PCs, TVs, websites | Sharing and uploading |
| MOV | H.264 / HEVC + AAC | Apple devices, most editors | iPhone recordings, Final Cut |
| WebM | VP9 / AV1 + Opus | Browsers, Android | Web video |
| MKV | Almost any | VLC and media players | Downloads, archives with subtitles |
Why WebM needs re-encoding
WebM uses VP9 or AV1 video with Opus audio, which many phones, editors and social apps won't accept inside an MP4. The converter re-encodes to H.264 and AAC — the most compatible combination — using your device's hardware encoder, so it stays fast.
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Frequently asked questions
- Why convert WEBM to MP4?
- WebM is an open web format (VP9/Opus) that many editors, phones and social apps don't accept. MP4 (H.264/AAC) is the universal video format that plays on every phone, computer, TV and website.
- Are my files uploaded?
- No. Processing happens in your browser using your device's built-in, hardware-accelerated video engine (WebCodecs), so your files never leave your device.
- How long does it take?
- Usually a fraction of the video's length on a modern computer or phone, because your device's video hardware does the work. Large 4K files take longer, and very large files are limited by your device's memory.