Excellent. Only reason it doesn't have a 5-star is because not sure how to allow Firefox Sync to also sync this extension. That would be killer!

Update (Aug 6, 2019): Not sure if it's a new release but my tab groups keep getting deleted! Please help.

It does follow the footsteps of Tab Groups of old pretty well. However, when I try to import a Tab Groups backup file, it doesn't do anything. Does anyone know of a solution? If this problem can be solved, the rating will definitely go up!

Overly complicated! When I open a tab group, and then close one of the tabs, that tab is PERMANENTLY removed from the group! WTF? If I wanted to remove it from the group I would have said so! I JUST wanted to close it!

Great work.

Juste génial, ça faisait vraiment longtemps que je cherchais ce genre de plugin. Fonctionne à la perfection. Merci au développeur

this is by far one of the best addons on here! finally I can bring some order into my forest of open tabs...

Extensions already have Load-Next-Group, Load-Prev-Group shortcuts, but no Load-Last_Active-Group shortcuts.

Load-Last_Active-Group shortcut is the most frequently used shortcut. But not now.

It is hoped that developers will see this evaluation.

The groups change automatically as you open and close tabs. That's not very useful.

Неплохое дополнение, даже без склероза, как у "Panorama Tab Groups". Единственная просьба перенести панель с кнопками управления группами и плагином снизу - наверх выпадающего меню. Так как при большом количестве вкладок туды пока долезешь - и рак свиснет. Сильно напрягает...

Great add-on that definitely satisfies the niche after tab groups was removed by default. I like that it helps mitigate the problem of having too many windows open by allowing those tab instances to stay alive but remain hidden.

Feature suggestions.
I enjoy the option "Create a new group when opening a new window!" So, here are some suggestions for window options that may go along with it: "open a new group in a new (or the current) window defaults" to speed up workflow, and "delete (or ask for the name of) a(n unnamed) group when closing a window" to reduce the accumulation of unused groups when opening and closing windows. You could also replace this option with one to "delete groups with zero tabs" or otherwise keep track of groups that have been opened by New Window. Another option could be to "

*update* I use this almost exclusively in one window now and it works really well with Sidebars. Thanks for the excellent work!