This worked perfectly for years. Nowadays, Firefox is good enough at blocking auto-playing media that I no longer need this add-on, but thanks for all the years of service 🙏

Works perfectly

Works great with latest Firefox Quantum even though it's been 3 yrs not updated.

Thanks for sharing this add-on, really worth it for which it has made more.Loved it!

Finally found something that works and this mutes also the first tab automatically.

It very easy to use it. There are no problems with it. I would like to use it. It useful. And I share it with my friends.