WEBM to MP4
Re-encode WEBM video to MP4 in your browser. Everything runs on your device, so even large files never leave it.
From
WEBM (.webm)
To
MP4 (.mp4)
Advanced options
Files whose codec MP4 already supports are repackaged losslessly and ignore both settings.
- When the source already uses a codec the target container supports, the file is repackaged rather than re-encoded — that is near-instant and completely lossless.
- Otherwise the video is re-encoded using your device's hardware encoder. Large files can take several minutes, so keep this tab open.
- Conversion uses the audio and video codecs built into your browser, so results depend on your device. Unsupported targets are greyed out.
Drop WEBM files here, or use the button below
Converted on your device — your files are never uploaded.
About these formats
- WEBM — WebM video
- Open, royalty-free web video — smaller files than MP4.
- MP4 — MPEG-4 video
- The default video format — plays everywhere, from phones to TVs.
- When the source already uses a codec the target container supports, the file is repackaged rather than re-encoded — that is near-instant and completely lossless.
- Otherwise the video is re-encoded using your device's hardware encoder. Large files can take several minutes, so keep this tab open.
- Conversion uses the audio and video codecs built into your browser, so results depend on your device. Unsupported targets are greyed out.
Other WEBM conversions
Private by design — no upload, no sign-up
This WEBM to MP4 converter runs locally, using your own browser. Your files are never uploaded to a server, so they stay on your device from start to finish.
- Are my WEBM files uploaded to a server?
- No. The WEBM to MP4 conversion runs locally in your browser using your own device's CPU. Your files are never uploaded, never transmitted over the network and never stored on a server.
- Is there a file size limit for WEBM to MP4?
- There is no imposed limit, because nothing is uploaded. The practical ceiling is your device's available memory, so very large files may be slower on older hardware.
- Does it work offline?
- Yes. Once the page has loaded, converting WEBM to MP4 keeps working without a network connection, since the conversion happens entirely on your device.
- Do I need to sign up or install anything?
- No. There is no sign-up, no account and no software to install. Pick a WEBM file and convert it to MP4 straight away.
- Is converting WEBM to MP4 free?
- Yes, it is free to use, with no watermarks and no daily quota.