MKVToolNix

Create, modify, and inspect Matroska (MKV) files. The essential toolkit for MKV video.

macOSWindowsLinux Open Source Media

MKVToolNix is the definitive set of tools for working with MKV files. Merge video, audio, and subtitle tracks into a single MKV. Split by duration or chapters. Extract tracks. Edit headers and metadata. The GUI wraps the powerful command-line tools. Free, open-source, and cross-platform.