Effing brilliant. Works perfectly for my use case of listening to Spotify while scrolling Reddit, pausing the music when I play a Reddit video with audio, then resuming the music when I've stopped playing the video. Thank you, Tonton Jo!! LEGEND

Works great, it even unmutes the previous tab if the stream in my current tab is silent for a while (I watch multiple streams at the same time and this is exactly what I needed)

This is nearly perfect, but 5 stars nonetheless. My only (small) gripe is it doesn't switch between foreground & background tabs the same way Smart Mute in Chrome does, meaning the new foreground tab will always play audio even when switched back to background unless the media is paused. I'm not sure if this is a Firefox limitation, but if I could switch audio seamlessly the same way it does in Chrome I'd be ecstatic! Either way thank you for bringing this to Firefox; I can't browse without it.

I have a suggestion. Currently If I play a video in one tab A, then play another video y tab B, tab B plays sound (ok), but if I go back to focus on tab A, the sound is not activated in tab A. I know there is a "mute all tabs but the active" add-on, but I want to edit online documents on a third tab while listening to two tv stations. Thanks for considering it. ^^

Edit: Nope. The whitelist does not serve me. I actually use a main work window (no sound) and two separate video windows (both with sound). The thing I'm trying to do is switch from sound on video 1 to sound on video 2 and mute on video 1 with a single click on the video that I want to attend to now. I know this is a niche request and probably very hard to do, but thanks for taking the time responding me.

Addon works perfectly. Finally found something that does what I need it to do. Excellent.