Video Converter (WebM ⇄ MP4)
Convert a video between WebM and MP4 for free, right in your browser. No signup, no upload — your file never leaves your device.
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WebM and MP4 are both common video formats, but they aren't always interchangeable — a video editor might expect MP4, while a website might prefer WebM for smaller file sizes. Instead of installing a desktop converter, this tool switches between the two formats directly in your browser, so you always have the version you need in seconds.
How it works
- 1Choose a video file — WebM or MP4, opened directly in your browser.
- 2Pick the format you want to convert to.
- 3Download the converted file once the conversion finishes.
Why use this tool
- Detects your file's current format automatically, so you only choose where to convert to.
- Re-encodes at a bitrate matched to your source video, keeping quality loss minimal.
- No file size limit beyond what your browser can comfortably handle in memory.
Frequently asked questions
Is this tool free to use?
Yes — completely free, with no signup, no account, and no limit on how many times you can use it.
Is my file uploaded to your servers?
No. Everything runs locally in your browser using your device's own processing power — your file is never uploaded, and we never see it.
Why would I need to convert between WebM and MP4?
MP4 has the widest compatibility across devices and platforms, while WebM often produces smaller files for web use. Converting lets you pick whichever fits where you're sharing the video.
Does converting reduce video quality?
The converter re-encodes at a bitrate matched to your source video, so quality loss is minimal and not noticeable in normal playback.
Which format should I choose?
Use MP4 if you need the widest compatibility across devices, video editors, and social platforms. Use WebM if you're optimizing for smaller file sizes on the web, since it often compresses more efficiently for the same visual quality.
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Written by the ScreenLaps team · Last updated August 2026
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