What Is a .mkv File? .mkv Format, MIME & How to Open

Quick facts

Extension.mkv

File typeMKV Video

MIME typevideo/matroska

CategoryVideo

Charset—

Compressible—

Format familymkv

What is .mkv

What is a .mkv file?

A .mkv file is a MKV Video — Open Matroska container supporting many codecs and tracks.

In the mime-db registry it maps to video/matroska. When serving .mkv over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to video/matroska — and is delivered over HTTP via the Content-Type header.

How to open .mkv files

Use VLC or MPV to open and edit .mkv files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: video/matroska

Common software that reads/writes .mkv:

VLCMPVHandBrake

Relation chain

.mkvextension of

format

mkvserved as

mime type

video/matroskasent via header

http header

Related extensions

Related MIME types

Common uses

Movies and clips
Streaming media
Screen recordings

How to edit .mkv files

Open the file with VLC, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .mkv files

Create a new file and save it with the .mkv extension, or export this format from VLC.

Frequently asked questions

What programs can open .mkv files?

Common options include VLC, MPV, HandBrake. You can also open many of these files with built-in viewers or a browser.

How do I create a .mkv file?

Create a new file in any text editor or the app that owns the format and save it with the .mkv extension.

What is the relationship between .mkv and the video/matroska MIME type?

video/matroska is the media type identifier used for .mkv files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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