Convert MP4 to MKV right in your browser
Free and unlimited, and nothing is uploaded: it all runs in your own browser. Open Video Converter
What changes when you convert MP4 to MKV
- Both formats are lossy. Re-encoding adds a second generation of loss, so keep quality high (80+) unless size matters more than fidelity.
- Both formats support animation; animated input stays animated where the target truly supports it.
- MKV video encoding exposes a quality control; around 80 is the usual sweet spot.
How to convert MP4 to MKV
- Add your MP4 file — drag it onto the page or choose it. It stays on your device.
- Pick MKV as the output format and set the quality slider.
- Press convert and download the result — individually or as one ZIP.
Questions
How do I convert MP4 to MKV for free?
Add your MP4 file on this site, choose MKV, and press convert. The whole conversion runs in your own browser — nothing is uploaded — and the MKV file downloads straight from your device.
Will converting MP4 to MKV lose quality?
Both formats are lossy. Re-encoding adds a second generation of loss, so keep quality high (80+) unless size matters more than fidelity.
Does MKV keep everything MP4 supports?
Yes within the format’s own limits — pixels, timing and structure survive the conversion.