Matroska

Matroska
MKV Extension Icon
Filename extension
.mkv .mk3d .mka .mks
Internet media type
video/matroska video/matroska-3d audio/matroska application/octet-stream
Initial release6 December 2002 (2002-12-06)
Latest release
1.7.2
19 July 2026 (2026-07-19)
Type of formatContainer format
Container forMultimedia
Extended fromMCF, EBML
StandardRFC 9559
Open format?Yes
Free format?Yes
Websitematroska.org

Matroska (styled Matroška) is a project to create a container format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. The Matroska Multimedia Container is similar in concept to other containers like AVI, MP4, or Advanced Systems Format (ASF), but is an open standard.

Matroska file extensions are .mkv for video (which may include audio, subtitles and chapters), .mk3d for stereoscopic video, .mka for audio-only files (which may include subtitles), and .mks for subtitles only.