Convert MP4 to MKV
Free, fast MP4-to-MKV conversion.
Video and audio are processed with ffmpeg in your browser — large files are slow and use a lot of memory. Keep files under a few hundred MB for best results.
About the MP4 and MKV formats
MP4. MP4 is the most widely-supported video container, ideal for sharing and streaming.
MKV. Matroska (MKV) is a flexible open container holding video, audio and subtitles.
Frequently asked questions
How do I convert MP4 to MKV?
Drop your MP4 files into the box above and click Convert. The MKV file is generated instantly and ready to download.
Will the quality stay the same?
MKV keeps full quality, so your converted file looks identical to the original.
Is MP4 to MKV conversion free?
Completely free, with no sign-up, watermarks or file-size paywalls.