MP4 to MKV Converter
Convert MP4 to MKV free, right in your browser.
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About the MP4 to MKV converter
The MP4 to MKV converter changes a MP4 file into MKV, right in your browser. Upload your MP4 file and download the MKV version — free, with no sign-up, no watermark, and nothing uploaded.
MP4 is the most widely supported video format — it plays on virtually every phone, browser and player. MKV (Matroska) is a flexible container often used for high-quality video with multiple tracks. The conversion runs on an in-browser build of ffmpeg, so your file is processed entirely on your own device and never sent to a server.
Frequently asked questions
- Is the MP4 to MKV converter free?
- Yes — completely free, with no sign-up, no watermark and no limits.
- Is my file uploaded to a server?
- No. It runs an in-browser build of ffmpeg, so your file is processed entirely on your own device and never uploaded.
- Will converting to MKV lose quality?
- Converting re-encodes the file to MKV, which is lossy, but the settings are tuned to keep quality high for everyday use.
- Why convert MP4 to MKV?
- MKV (Matroska) is a flexible container often used for high-quality video with multiple tracks. Converting to MKV makes the file easier to use wherever MKV is expected.
- Why does the first run take a moment?
- The first time, it downloads a ~32 MB processing engine, which is cached afterwards so later conversions start instantly.