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Convert.webm

Convert WebM to MP4 online

100% localFiles never leave your device — no upload, no account, no tracking.
About WebM to MP4

Convert WebM videos into MP4 so they play on devices and apps that don't support the WebM container. We re-encode to H.264 with ffmpeg.wasm at the quality you choose for maximum compatibility.

The conversion runs entirely in your browser. Your WebM file never leaves your device, so the process is completely private.

How it works
  1. 01

    Add a WebM

    Drop your WebM file onto the page or pick it from your device.

  2. 02

    Set quality

    Choose a CRF value for the output quality.

  3. 03

    Convert

    Click Convert to encode an MP4 locally with ffmpeg.wasm.

  4. 04

    Download

    Save the MP4 file.

Features
H.264 outputbroad compatibilityadjustable quality
Frequently asked
How does the WebM to MP4 converter work?
Convert WebM videos into MP4 so they play on devices and apps that don't support the WebM container. We re-encode to H.264 with ffmpeg.wasm at the quality you choose for maximum compatibility.
Are my files uploaded to a server?
No. Everything runs entirely in your browser using local JavaScript and WebAssembly. Your files never leave your device.
Does it cost anything or require an account?
No. The converter is free, needs no sign-up, and runs locally in your browser.
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