MKVToolNix muxing settings
File type: Settings, options, themes or skins file
The mmg file extension identifies a saved MKVToolNix muxing project or settings file.
An mmg file belongs to the graphical interface of MKVToolNix and stores settings used to create Matroska files.
File type category:
Settings, options, themes or skins file
Date updated: October 9, 2026
MKVToolNix is a set of tools for creating, altering and inspecting Matroska (MKV) video files. It is available for Microsoft Windows, Apple macOS and Linux.
The mmg file stores muxing settings for the MKVToolNix graphical interface. It contains project information rather than the resulting video itself. The extension is mainly associated with the older MMG interface and is a legacy settings format.
Open an mmg file in the MKVToolNix GUI on Windows, macOS or Linux and select the file using the appropriate file command.
The file is loaded as a saved muxing project, allowing its settings to be reviewed or used again. It is not opened as a playable video.
An mmg file is a settings file, so it has no meaningful media conversion. Open it in the MKVToolNix GUI and use the saved settings to mux the selected sources into a Matroska file.
Software apps that manage or store settings in mmg files:
Microsoft Windows
Apple macOS / Mac OS X
Linux/Unix
Language
