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Free Video Converter

Convert video between MP4, WebM, MOV, MKV, and AVI. Great for making WebM play on iPhones or turning MOV into MP4. No upload — runs in your browser.

Drop a file here, or click to browse

MP4, WebM, MOV, AVI, MKV, M4V · processed on your device

or press Ctrl+V to paste from your clipboard

Browse files

Your files never leave your device. All processing happens locally in your browser.

Common uses

  • Convert WebM to MP4Turn a WebM video into MP4 so it plays on iPhones, iPads, and any device that can't open WebM.
  • Convert MOV to MP4Convert iPhone/QuickTime MOV recordings into universally compatible MP4 files.
  • Convert MP4 to WebMConvert MP4 to WebM for smaller, web-native video on your own website.
  • Convert MKV to MP4Convert MKV files into MP4 for players and devices that don't support the MKV container.
  • Convert Video for EditingConvert clips into a format your editing software can import cleanly.

How It Works

Converting between video containers and codecs normally means uploading to a conversion site. This converter runs the real FFmpeg engine in your browser, so the file never leaves your device.

  1. 1
    FFmpeg.wasm loads once
    The WebAssembly build of FFmpeg (~30 MB) downloads on first use and is cached for instant reuse.
  2. 2
    You pick a target format
    Your video is loaded into FFmpeg's in-memory filesystem. Nothing is uploaded — it stays in your browser's RAM.
  3. 3
    FFmpeg re-encodes to the new format
    The same x264/VP8/MPEG-4 encoders desktop FFmpeg uses run locally on your CPU to produce MP4, WebM, MOV, MKV, or AVI.
  4. 4
    The converted file is offered for download
    The result is handed back as a downloadable blob and (for web-playable formats) previewed in-page.

A common need is making a WebM play on an iPhone (iOS Safari can't play WebM) — converting to MP4 fixes it instantly, with no upload, no queue, and no watermark.

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Frequently Asked Questions