: All data processing and file merging occur locally within the browser; the extension does not collect user information or store download history on external servers. How to Use MPMux on Firefox
This setup is often referred to as a "user script" or "protocol handler" solution, popularized by tools like (now yt-dlp ). mpmux for firefox
Since Firefox cannot execute system binaries directly from a web page (for security reasons), the safest method is: : All data processing and file merging occur