Seemed nice, but when I've first time changed to a group of a few selected from many tabs it hid them without an easy way to change back to the ungrouped ones.
I've found them under the "v" tab menu and saw an option to change them into a group, which I used, as I saw no other way to get back to tabs without groups. After a few minutes of CPU abuse the "Ungrouped" group had zero tabs. 400 tabs went straight to /dev/null.
So yes, a good way to clean out your stale tabs, short of removing your profile.

Edit: Now I'm torn, as I've found out how the "Manage groups" looks and works.

Nunca escribo reseñas. pero esta extension me dio justo lo que necesitaba, habian eliminado de firefox el agrupar pestañas en grupos. y esta extension me permitio poder hacerlo nuevamente. Muchisimas gracias.

The Very Best of the Best! Perfectly working, simple, fun to use, highly configurable, actively being developed from a very polite and professionally responding to concerns developer! HIGHLY RECOMMENDED!

the best extension ever

It's almost perfect. One thing is missing: an optional ability to remove empty tab groups (with unmodified title) automatically. I guess, this would be a quite easy feature and could help a lot.

shout-cut key (e.g. alt + e) not work in https://komica.org/

Sangat Bembantu

1. When i take "url" manage groups from adress bar (for example moz-extension://8e9a54bb-e738-413f-ae0e-f28052cf45da/manage/manage.html) and make this url my home page, and then use hotkey or gestures to start homepage - manage groups starting, but tabs in groups deleting after transitions to other groups. Its sad.
2. Tab "manage groups" not deleting if i run manage groups and select other tab in current group, i forced periodycaly delet this tab. And why tab "manage groups" visible in manage groups?
3. Window "manage groups" does not remember window position and size, and why i cant maximaze window?
That's all for now, tnx.

Immensely useful extension!

It can be configured (per-group!) to unload tabs from inactive groups, making it possible to have >100 tabs open on an older laptop with little memory, somewhat like Snooze Tabs but more organised.

It also has a sidebar with a searchable vertical tab view, which I've found less of a faff to use than the Tree-style Tabs extension.

It integrates well with the container functionality in Firefox, and the dark theme isn't broken.

This one feels a bit like uMatrix in that it's one extremely well designed and well thought out extension that does the work that you'd otherwise need at least half a dozen other extensions for.

Although it may be difficult to grok at first (as in "Why would I even need tab groups as well as tab containers?"), this is super helpful for navigating tabs, keeping focus on specific tasks and improving browser performance.

Not a huge deal but whenever I pin a tab so that I can see it in all groups it always seems to create a new group

Me gustó el complemento, me parece fácil de usar y mejora la gestión de pestañas.

Orientation – discovery of the sidebar etc. – as a former user of Tab Groups with Waterfox Classic:

https://github.com/Drive4ik/simple-tab-groups/issues/319#issuecomment-602030530