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!

Hello, could you sign your add-on, because this add-ons is no more available since Forefox has desactivated every add-ons non signed. Thank you.
https://developer.mozilla.org/en/docs/Mozilla/Add-ons/Distribution

A well-designed and multi-featured add-on.

Update: Sorry, I missed that option. Well, that settles the only complaint I had about the add-on. Thank you.

Plugin awesome. I can not live without it.

Thanks!

Довго шукав заміну для застарілого додатка, це найкращий додаток на даний момент, що дозволяє групувати вкладки

Awesome Add-On, I cannot live without it. However, it seems that with latest Firefox update it got disabled (Add-On needs to be signed) any ETA for it ?

Very good extension, thanks a lot !

I am using Firefox 66.0.3, addon version 3.4.3, Windows 7 64bit.
I forgot to mention that it happens not every time.
You can contact me at alexjzx (@) gmail.com.
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Add-on is really cool and it does the job well, but:
1) It takes too much time to load tabs, about 2-3 mins for ~60 tabs
2) Until it is loaded, you re not gonna to do anything to your tabs, because it will load tabs state in 3 mins and will erase all your progress(e.g. newly opened tabs)
3) Thus, it slows down starting your work with the browser.
For the rest, this addon is great and highly usable.

Absolutely fantastic add-on! Great for organizing many open tabs and windows. Note one thing that was not very clear early on for me is that each group is associated with only one window. So you cannot have multiple windows associated with a single group. Although I did not expect this at first, this approach gives a very fluid user experience. I cannot recommend this extension enough if you are like me and tend to keep many tabs and windows open for an absurd amount of time and return to them later.

One slight annoyance is how, from what I can tell, there is no easy way to convert a window that is not associated with a group to be a new group. If you select ALL open tabs in a window, use "Move tab to group" to a new group, it closes the window you were just on, changes the current window to another one, and changes that window to the newly created group. Expected behavior is to keep the window open when creating a new group for all tabs on the the current window.

The previous bug is fixed and I gave the extension 5 stars. But, it is very annoying when the extension spontaneously hides tabs when switching groups. Can you tell me how to disable hiding tabs?

I've been holding off updating Firefox until this add on became stable. Over the last week I have been running it in in parallel with my production environment with ~ 150 open tabs in 5 groups and had no issues with load times, overall performance or stability.
Consequently, I have today fully transitioned to FF V65.01 and Simple Tab Groups.
Am very happy. Great work! Thank you.

非常好用，在以前FireFox內建的「分頁群組」被拿掉之後，這個tab管理套件算是很不錯的。