MP4 to MKV
Convert an MP4 (or any other video) to MKV. MKV (Matroska) is popular with players like VLC, Kodi and Plex.
Free · No sign-up · Files stay on your device
How to use MP4 to MKV
- 1Choose your video.
- 2Click "Convert to MKV".
- 3Download the MKV file.
Features
- MKV output
- Works with MP4, MOV, WebM, MKV and more
- Keeps the original resolution
- No upload, no watermark
- Free
About MKV
MKV can hold almost any codec, so MP4 videos are usually copied into it instantly without re-encoding.
Private, in-browser processing
This tool uses FFmpeg, the open-source engine behind most professional video software, running inside your browser. The first time you use it, the engine (about 30 MB) is downloaded once and then cached, so later conversions start straight away.
Frequently asked questions
Are my files uploaded?
No. Processing happens on your device with FFmpeg compiled to WebAssembly, so your video and audio never leave your computer or phone.
Why does it take a while?
Video processing is demanding, and your browser does it on your own device instead of a big server. Short clips take seconds; long or 4K videos can take several minutes. Keep the tab open until it finishes.
Will the quality change?
Usually not at all: when the codecs are compatible, the video is copied into the new container without re-encoding.