It can be a bit buggy at times, but when it comes to just playing music with the screen locked, it’s perfect.
https://addons.mozilla.org/en-US/firefox/addon/video-background-play-fix/
Edit: I forgot to also mention that ad blocker extensions make sailing the seas on mobile much more manageable. Extentions, in general, have been a really nice addition.
BE WARNED. These extensions are a prime target for purchase and/or hijacking by malicious threat actors, who then use them to gain persistence on your browsers and steal data. There is no reason to increase your browser attack surface for this feature when better alternatives have been posted in this thread.
https://www.bleepingcomputer.com/news/security/chrome-extensions-with-14-million-installs-steal-browsing-data/
https://arstechnica.com/security/2025/01/dozens-of-backdoored-chrome-extensions-discovered-on-2-6-million-devices/
There are dozens of these articles dating back the last five years or so.
To top up your comment, you can get the permissions required for each extension in Firefox for Android. Extension Manager --> click the extension --> Permissions
In the case of this specific extension, it requires access to the data of only 3 domains :
Many other extensions are far worst in regards to permissions that this one.
It is a good habit to check what are the permissions required before using any extension or phone apps for that matter.
Thanks for the reminder!