the main reason why I prefer Firefox to any other browser

Having separate cookies for each container is an absolute godsend!
The thing I really miss is, that you aren't able to set containers in bookmarks, that's why I deducted a star.

On YouTube, I have a container for each of my channels, so I don't have to switch accounts constantly, and each container is saved as a separate bookmark, so I can access that channel easily.

For the time being I installed a separate extension to solve this, but imho, this should definitely be solved in this extension, since this is a very basic/common request I would imagine.
https://addons.mozilla.org/en-US/firefox/addon/container_bookmarks/

This is very useful. Thanks for building it.

Cool app. The only problem I have is duplication of containers on firefox updates. Not every update though.

It will open links to other websites into the same container if clicked on. It would be nice to have an option to disable this

Работает прекрасно!

sangat bermanfaat untuk buka banyak akun.

Love it use it all the time.