How to Use MPMux in Firefox: Client-Side MP4 Audio Editing
If you work with MP4 video files—especially those with multiple audio tracks (e.g., commentary + original audio)—you’ve likely heard of (part of the Bento4 suite). Traditionally a command-line tool, many Firefox users are now asking: Can I run mpmux directly in my browser?
3 min
April 14, 2026