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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.

No file size limitFiles stay privateNo login requiredFree forever

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MP4, WebM, MOV, AVI, MKV, Video no file size limit

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

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Convert WebM to MP4 Convert MOV to MP4 Convert MP4 to WebM Convert MKV to MP4 Convert Video for Editing

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
FFmpeg.wasm loads once
The WebAssembly build of FFmpeg (~30 MB) downloads on first use and is cached for instant reuse.
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
FFmpeg re-encodes to the new format
The same x264/VP9/MPEG-4 encoders desktop FFmpeg uses run locally on your CPU to produce MP4, WebM, MOV, MKV, or AVI.
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.