Convert MP4 to MKV
Turn MPEG-4 video files (.mp4) into Matroska video (.mkv) in seconds. Drop one file or a whole batch: the conversion happens right in your browser, with no sign-up, no watermark and no upload.
MKV to MP4 insteadHow to convert MP4 to MKV
- 1Drop your MP4 files into the box above, or click to choose them.
- 2MKV is already selected. Adjust the options if you like.
- 3Click Convert and download your MKV files.
Good to know
- When the video and audio codecs are allowed in MKV, the streams are copied without re-encoding, which is fast and lossless. Otherwise they are re-encoded with a quality you choose.
- Large videos are processed as a stream, so even long files work as long as your device has enough memory.
Frequently asked questions
Is converting MP4 to MKV free?
Yes. There is no sign-up, no watermark and no limit on the number of files.
Are my files uploaded?
No. Everything runs in your browser, so your files are never uploaded to a server. That also makes it fast, because nothing has to travel over the network.
Will I lose quality converting MP4 to MKV?
MKV stores the result with some loss. With the default settings the difference is hard to notice, and you can raise the quality if you need to.
Can I convert several files at once?
Yes. Drop as many MP4 files as you like. They are converted one after another and you can download them individually or as a ZIP.
Is there a file size limit?
There is no fixed limit. Very large files depend on your device's memory, since the conversion runs locally.
What is MP4?
MP4 is the most widely supported video format, playable on phones, browsers and TVs.
What is MKV?
MKV is a flexible open container that can hold many video, audio and subtitle tracks.