Convert MKV to MP4
Turn your MKVs into MP4 that plays everywhere (H.264 + AAC), without uploading the file anywhere.
Your files never leave your device
How to convert MKV to MP4
- 1
Upload the MKV
Recordings, captures, downloads…
- 2
Convert
Re-encoded to H.264 + AAC with faststart.
- 3
Download the MP4
Compatible with everything.
Why use this tool
Total compatibility
MKV won't play on many phones and TVs; MP4 will.
Edit-ready
Editors accept MP4 far better than MKV.
Web-ready
faststart: playback starts before the file finishes downloading.
Private
The video never leaves your device: ffmpeg runs in your browser.
Frequently asked questions
Why re-encode instead of copying?
Many MKVs carry codecs (VP9, 10-bit HEVC, subtitles) the MP4 container can't hold as-is. Re-encoding to H.264 guarantees the result always works.
Are subtitles kept?
No: MKV subtitle tracks are dropped in the conversion. Extract them first if you need them.
How long does it take?
Depends on duration and your machine: re-encoding runs frame by frame in the browser.
Is quality lost?
CRF 23 keeps the visual quality very close to the original.