01
ADD YOUR MP4
Drop the MP4 file into the box above or choose it from your device.
MP4 → MKV / online converter
MP4 to MKV Converter
Convert an MP4 video to MKV for media servers and players like Plex, Jellyfin and VLC.
01 / how to
How to convert MP4 to MKV
02
CONVERT TO MKV
MKV is already selected. Press Convert and wait a few seconds.
03
DOWNLOAD
Save the finished MKV file. The original is deleted from our server.
02 / what you get
What happens to your data
Kept
- H.264, H.265 (HEVC, the iPhone and Android default) and other common codecs are read
- H.264 video with AAC audio in a Matroska container that plays in VLC, Plex, Jellyfin and most media players
- The original resolution and frame rate are kept
- A phone video recorded sideways or upside down is turned the right way up
- Surround sound (5.1) is kept when the source has it
Good to know
- The video is re-encoded, which is slightly lossy. Only one video track and one audio track are kept; extra audio tracks and subtitles are left out.
- A width or height that is an odd number of pixels is trimmed by one pixel, because video encoders need even sizes.
- HDR video (for example from a recent iPhone) is converted to normal SDR colors, and 10-bit video becomes 8-bit, so it plays everywhere.
- Files up to 150 MB are accepted. Long or very high-resolution videos can take several minutes, and a conversion that runs past about 4 minutes is stopped with a message.
03 / formats
MP4 vs MKV
MP4
An MP4 file is the most universally supported video container — plays on every device, browser, and platform. The default choice when you're not sure what format to use.
Used in: Universal playback · Sharing · Web video
MKV
An MKV (Matroska) file is an open-standard, highly flexible video container — popular for media archiving, torrents, and playback through apps like Plex or Jellyfin.
Used in: Media archiving · Plex & Jellyfin · Torrents
04 / more
More conversions
Have a different file? Open the main converter — it detects the format for you.