As soon as the extension is deactivated, almost all data is erased! There is no way to recover anything and you cannot make a backup! This makes it INUSABLE. This is a very serious problem that has never been solved!!! Why don't you use Firefox Sync?

Mozilla set big expectations for this extension, but it did not work at all in Firefox 84.0 for Mac. I installed and enabled it, but the add-on's icon never appears in the toolbar and right clicking on web links does not present an option to choose a container. In the manager for the add-on, I created new containers in addition to the defaults and they disappear as soon as I exit the manager and re-enter it. A perpetual warning message appears in Firefox's Preferences indicating "An extension, Firefox Multi-Account Containers, requires Tab Containers," as though they are not enabled and need to be. Yet the checkbox for Enable Tab Containers right below that warning is enabled. So tab containers appear to be enabled, but the add-on is completely non-functional and worthless, and there are no help articles that address the problem of the icon not even showing up and no container-choosing functionality appearing after install. Mozilla set big expectations or this add-on and delivered a big disappointment.

Nothing was shown by site mangers. It's quite unti-user friendly.

Amazing addon, I use it every day.

I like it very much, but the problem is that I can't sort the containers.
As the number of infrequently used and infrequently used containers gradually increases
The priority will change, such as what you want to use in the future, so we would appreciate it if you could add a sort function.

Really useful, now i need it for the android app

Much appreciated to have this option. Love it to keep google out of my other tabs but youtube :)

Couldn't live without it. Only thing that would be better is a system context menu to target containers when clicking links in other sources.

This is a must have extension, and it makes Firefox very awesome.