Hi   !

Before you minimize : click te speaker button on the tab, or (better still) : press the mute key on your keyboard (unless your keyboard doesn't have that key).

Also see : https://support.mozilla.org/en-US/kb/mute-sound-firefox-tabs

There is an add-on, but I wouldn't recommend it, as it hasn't been updated for years and probably won't work with Firefox 57 + :

https://addons.mozilla.org/en-US/firefox/addon/muter/

Thanks for your reply. I'm familiar with the speaker button on the tabs which is very handy. However, I need to have something that just auto mutes Firefox when I minimize it without the need to click the speaker.

Regards

This may not be what you want either, but giving it a shot anyway :

Type in the address bar about:config (press Enter) (promise to be careful, if asked) Type and look for the preference : media.block-autoplay-until-in-foreground and set its value to true

Beauty, and brains too.

Nopes didn't do the trick. Thanks for the suggestion though.

MM6631764 said

Nopes didn't do the trick.

Bummer  ! Guess I'm going to need better working braincells, for I can't come up with anything else ...... (so sorry  !)

Keeping my fingers crossed that somebody else wil come up with the perfect solution for you .......

Do you want to stop the active player(s) or only mute the sound?

Maybe this extension:

• Sound Control:
  https://addons.mozilla.org/en-US/firefox/addon/sound-control/
• Mute Tab (WebExtension): https://addons.mozilla.org/en-US/firefox/addon/mute-tab-webextension/

More:

• https://addons.mozilla.org/en-US/firefox/search/?q=mute