Compress an MKV video (and convert it to MP4)
MKV (Matroska) is popular for OBS recordings because it survives crashes, but many apps and phones won't play or accept it. Compressing it here converts to H.264/AAC MP4 in the same pass, so the clip becomes both smaller and shareable almost everywhere.
Last updated September 2026
Compress an MKV →How to do it
- Open the compressor.
- Load your .mkv file.
- Choose a target — Discord (10 MB) for clips, or a custom size for longer recordings.
- Set 720p for long gameplay; keep 1080p for short highlights.
- Compress and download the MP4.
Tips
- If your OBS setup records mic and game audio to separate tracks, mix them into one track in OBS so the clip has all the sound you expect.
- Long, high-bitrate MKVs may exceed browser memory — trim the part you need.
FAQ
Does it convert MKV to MP4?
Yes. Video output is always an H.264/AAC MP4.
Why won't my MKV play on my phone?
Many phone players and social apps don't support the MKV container. Converting to MP4 fixes that.
Is anything uploaded?
No. The MKV is processed locally in your browser.