After many years of using Firefox and other browsers, Tab Stash is the first extension that's made it possible for me to keep the number of tabs I have open under control. Its UI is thoughtfully designed to make common actions take as few clicks as possible, in contrast to using the browser's built-in tools. This extension is as indispensable as uBlock Origin. Thanks to the author, Josh!

Amazing for research - has completely optimised my workflow! Now I cant live without it. The recent sub-groups update is perfect for organisation too.

If you've come from Google Chrome to here and are trying to find a grouping extension that's similar, this one is! Instead of grouping them in the top bar, you'll have a little sidebar. BUT, the important thing is that it will let you close out of tabs on your main slider without actually deleting them. So, if you don't like having a bunch of windows open or tabs up on your slider, you won't have to!! You can even open one tab at a time or the entire group. An absolute lifesaver for me :)

This extension is the perfect marriage between tab mgmt and bookmarks. This should be a default Firefox feature

Great add-on. Specially useful for managing multiple sessions on a single site, such as Gmail.

searching for tab outliner alternative in firefox, and this is it(much better than tab outliner in my work flow)

Recommend. Very handful addon for users that have lots of tabs and want to separate them into convenient workspaces. Thanks to the dev, I appreciate your work.

Updates after 2 weeks of usage: add-on works really smoothly. Didn't notice any bugs so far. Definitely recommend to use, 10/10.

Thanks for this wonderful extension. I came from OneTab, disappointed by not being able to sync the groups between my devices. With Tab Stash, everything works as a breeze. Super UI, great UX: I cannot imagine a feature I would miss. Tab Stash fulfills my needs.

Super easy to use and it does it's job perfectly.
It has quickly become my favorite extension

Edit: the 3.0 update is AMAZING

Great for saving sessions. Although I do wish it were compatible with Tree Style Tabs. It would be even greater if Tab Stash saved the tab nesting as well.