Compare software

FFmpeg vs MKVToolNix: catalog facts
FFmpeg	MKVToolNix
Free Free and open source. The codebase is mainly LGPL 2.1 with some components under the GPL…	Free Free and open source under the GPL 2.0.
Windows, macOS, Linux, Command line	Windows, macOS, Linux
Handles practically every container and codec there is Remuxes without re-encoding, so a container change is instant and lossless	Adds, removes and retags tracks without re-encoding anything Header editor for fixing default track flags and languages
Command line only, with syntax that punishes guessing Argument order matters in ways that are not obvious	Matroska output only Cannot change the video or audio encoding at all
Downloadable app	Downloadable app
Open source	Open source
License: LGPL-2.1	License: GPL-2.0
No account needed	No account needed
Works offline	Works offline
Official website Full listing and sources Checked September 21, 2026	Official website Full listing and sources Checked September 21, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.