An MKV file is a video file saved in the Matroska multimedia container format. It supports several types of audio and video codecs and may include .SRT, .SSA, .USF (Universal Subtitle Format), or VobSub subtitles. MKV files are typically used for storing short video clips, TV shows, and movies.

MKV file open in Microsoft Movies & TV The Matroska multimedia container format is open source and was originally released in December 2002. It is similar to the .AVI, .ASF, and .MOV formats and can contain any number of video, audio, image, and subtitle tracks. Multimedia files that utilize the Matroska container format and store one or more video tracks are known as Matroska Video files, and are distinguished by the .mkv file extension. While the MKV format is often used to store short video clips, TV shows, and movies, it has become popular in the anime fan-subbing community. Many of these users create subtitles and the MKV format is especially useful since it supports multiple audio and subtitle tracks in the same file. The MKV video format is not as common as the .MP4, MOV, and AVI formats. However, many media players still support MKV files, such as Microsoft Movies & TV, VideoLAN VLC media player, and MPlayer. NOTE: The Matroska name comes from the Russian Matryoshka doll that contains numerous smaller, nested dolls of the same shape.