2.1.0 update Because of the feedback about the add-on requesting permission to access data for all websites. Instead of setting up scripts for all pages, in this update the add-on inject the script into pages when needed. Anyway, the add-on still have to inject scripts into pages in order to change the output device. If you still have any concern, I suggest using this add-on as a bookmarklet. This way you don't need to install any add-on to do the output changing. Find more information here: Github For Firefox ESR or previous version user The new version of this add-on (2.0.0) only works on Firefox 92.0 and after. You can install the old version in the version history. ------ A extension to select specific audio output device for each tab. Works on HTML5 <audio> , <video> element You will need to enable media.setsinkid in Firefox to use this add-on.