Open MP4 File

MKV File

MKV file extension is used to store files in Matroska Multimedia Container format. Matroska is an open source and license free container format which can store video, audio and subtitles streams in the same file and synchronize them by time code.

Matroska specification supports following key features:

• Support for various levels of metadata including chapters and menu
• Storage and selection of multiple audio and video streams
• Support for online streaming
• Support for hard-coded and soft-coded subtitles
• Playback of partially corrupted files with error recovery
• Fast seeking back and forward

Windows 10 has support for MKV files starting from October 2014. When you try to open MKV files on Windows 10 it will open in Movies & TV app. If you use a previous version of Windows operating system you can download and install a free VLC Media Player application. VLC Media Player is able to open lots of different media formats including MKV.

Mac OS doesn’t support MKV by default. You will need to download VLC Media Player or another media player with MKV support.

iOS and Android also do not support MKV out of the box. You will need to download VLC app from the App Store of Google Play Store to enable MKV support. Many others mobile media apps available can also play MKV files.

Matroska uses Extensible Binary Meta Language (EBML) as its binary storage format which makes it easily extensible. EBML is a binary equivalent to XML and provides a framework for storing XML like tags in a hierarchical tree like structure.

Matroska libraries are licensed under GNU Lesser General Public License. Parsing and playback libraries are licensed under BSD license. Matroska standard is completely royalty free with its technical specifications available for private and commercial use. This made Matroska one of the most popular audiovisual container formats on the internet.

WebM audiovisual container file structure is based on Matroska media container format together with VP8, VP9 or AV1 video and Vorbis audio.

Following alternative extensions could be used:

• MK3D is used for stereoscopic video
• MKA is used to store audio only content
• MKS is used to store subtitles

To transfer MKV files over internet following Internet Media Types (formerly known as MIME types) are used:

• video/x-matroska
• audio/x-matroska