WebMMP4
Free & private

Convert WebM to MP4

Fast, free, and completely private. Your videos are converted right here in your browser — no uploads, no watermarks, no waiting in line.

Drop your WebM files here

or click to browse. Convert as many files as you like — all in your browser.

100% Private

Files are converted locally in your browser. Nothing is ever uploaded to a server.

No Limits

No file size caps, no watermarks, no sign-up. Convert as many videos as you want.

Works Offline

Once the page loads, conversion runs entirely on your device — no connection needed.

High Quality

Powered by FFmpeg with H.264 + AAC encoding for broad compatibility and crisp output.

How it works

  1. 1Drop or select one or more .webm files.
  2. 2The converter runs locally in your browser and shows live progress.
  3. 3Download your ready-to-use MP4 files — that simple.

Frequently asked questions

Is my video uploaded anywhere?
No. This converter uses WebAssembly (FFmpeg compiled for the browser), so your files are processed entirely on your own device. They never leave your computer.
Is there a file size limit?
There is no hard limit imposed by us. Because conversion happens in your browser, the practical limit depends on your device memory. Very large files may take longer or require a desktop browser.
What formats does the output use?
Your WebM video is converted to an MP4 file using the H.264 video codec and AAC audio, which plays on virtually every device, browser, and editor.
Is it really free?
Yes, completely free with no watermarks, no account, and no ads interrupting your conversion.