Not clear how to hide tabs

[Kelvets]

Been looking for a replacement for Simple Tab Groups, where I grouped several tabs for things that I only visit seldomly (e.g. a group for manga reading), and these tabs are kept hidden. I tried to simulate this behavior with this extension:

Notice I moved the manga tabs to their own container, but they are still present in the same window as the "No container" (they're the rightmost half of the open tabs). How do I hide them from view?

[JohnLGalt]

Once you have them in the container that you want, close the ones in the container where you no longer want them.

This extension is far more than just tab groups, because it makes use of Firefox's native Containers feature, which are not just a grouping of tabs, but rather fully isolated containers, each (container) with its own cookies, history, etc. This allows you to have the same website open in different containers and be logged into said website with completely unrelated credentials - and neither sees the presence of the other.

In that respect, I suspect that actually "moving" tabs between containers is not possible, as all that background stuff, like cookies, etc. doesn't get copied over, so the only way I know of to do it is as you have done - reopen in a new container, then log in there (if a log in is needed) then go back and close the original.

[metastable-void]

Copying cookies and bringing them around, is technically possible and partially implemented for the "copy cookies from" option during container creation. Though fully cloning sessions is not possible, because there are many storage APIs not exposed to WebExtensions.