The add on is really great and an amazing productivity boost. Unfortunately, just now I lost all my tabs in the addons grouping functionality - one day some tabs could not be clicked on to switch to it so I restarted and all was lost apart from the ungrouped group. Not sure what happened.

Excellent, but somewhat bloated if you only want vertical tab without the tree hierarchy. Few issues here and there.

I've had to downgrade my review because of one tiny but huge thing. For a very strange reason, the author has chosen 'F2' to show/hide the panel. This is not a good choice as F2 is universally used for 'edit'. So i've had to disable/remove this add-on because it kept showing/hiding and stealing the focus through the use of this shortcut. My example is through using Google Docs.

I humbly request he changes the default to something that isn't so commonly used and perhaps a two-key combo (Win+F2?). On top of changing the default, i suggest making it customisable. Thanks.

Great addon, the save session (and even group) function is indispensable for me. Every time I launch FF, I need certain tabs open by default. Saving my sessions through this addon lets me load up what I was last working on, and merge in any default tabs that I need. Very good addon, I highly recommend if you want to save your tabs and quickly get back to work. One thing though! This is the only bug I have encountered; The tabs sometimes will stop responding to clicks, and sometimes its not just selecting tabs but specifically moving them (one or the other, though). Simply closing tree tabs, and then clicking on the icon to get it back up fixes the problem. A little annoying but worth the effort since this addon saves me so much time.

Kroppy, you've done all us FF users a great service - THANK YOU! As a long-time user of Tab Folders (and all the various add-ons that worked up until WebExtensions killed all the great add-ons I'd used for years) I was in limbo until I stumbled on TT. You've given us all a way to organize the dozens of tabs and access them easily. And you listened to all of us begging for folders and groups and you built that in, as well.

Now I just need an idiot-level tutorial to figure out how to USE all these marvelous tools...

Has a very annoying feature; once in a while it loses tree structure when ff gets restarted.

Great add-on, cannot live w/o it - nicely replaced the old tab groups manager & helper. Feature request - is there a way to allow right click the tab and let me save bookmark?

EDIT: DON'T INSTALL TAB SESSION MANAGER.

Kroppy, thank you very much for the tip. After removing TAB SESSION MANAGER, your extension now works perfectly. Maybe adding that information to the description and/or work with the owner of that extension to make both compatible.

This is the most wonderful extension for Firefox, period.

First impressions: I'm just now testing Tree Tabs, as a long-time Tree Style Tab user who's followed Tree Tabs from the first Vivaldi forum posts. It has some very nice features out of the box. I love the groups, unloading, and session backups, as well as the auto-correcting tab order for keyboard shortcuts.
Additional thoughts: So far, pretty awesome. Literally replaces three extensions, and very nearly three more, at least. Groups, tree-hierarchical tabs, and tab search are fully replaced, and it almost replaces a session manager, tab-unload manager, and an undo-close menu.
If wishes were... : It'd be helpful to have the session feature save automatically every x minutes and allow selection of a session to load. Tab-unloading would be more useful if it could be automated on a timed basis with a whitelist. Undo-close would be nifty if it had a list of the last few closed tabs, but it works fine as-is.

Bugs: None found yet?
Noteworthy: The audio icon only appears on that specific tab, even if it is within a collapsed tree. This can be a bother if more than one tree or branch of possibly-guilty tabs exists. It might be better to display the icon on the nearest visible parent tab, if the playing tab is hidden, as well as on the group title, to aid in locating an offending tab, especially in cases of sneaky, ill-behaved ads, but also for those who (over)(ab)use YouTube and the like.
Edit: Found the sidebar unresponsive at times. The problem was predictably resolved when I disabled my session manager and a tab-unloading addon. Seems that many (most?) things that interact with tabs directly may interfere with Tree Tabs.

I use this as a replacement for the discarded panorama feature. Tree structure proves to be handy or even extremely useful. A spot-on use of the lateral panel, making for a perfect integration.

Still sketchy in nightly (currently 61) with new windows popping up when dragging tabs. Otherwise, quite stable and reliable. [Edit] As of Nightly 61, no tab dragging issues after several hours testing in 61. So I was wrong, nothing sketdchy about it :). Awesome!

I would still browse pre-quantum if it wasn't for this. THanks indeed.

Seems to break the lateral panel or rather lock it down. I installed an experimental feature (notes) which uses the side panel as well. NO dice. I suppose it's worth looking into it here :
https://testpilot.firefox.com/experiments

Basically a great addition. But the order of the tabs in Tree Tabs vs. what Firefox thinks the order to be is completely off. If you close a tab you never know where you will land next. In the preferences you can set that the next tab should be the one above/below, but this does not work reliably.
I make heavy use of the "group" feature and more often than not the tab I land is an a totally different group.

This extension makes me say "WOW!" It has so much functions to control tens and hundreds of tabs.. Definetely more fucntional than Tree Style Tabs plugin which I used before, I going to use this plugin instead.

Спасибо за последнее обновление! Стало работать гораздо лучше и удобнее.

Однако появился новый баг. Точно описать его пока не могу. Суть в том, что актуальная родительская вкладка может переместиться в предстоящую родительскую при открытии дочерней и так-же переместиться обратно при просмотре дочерней. Сам до конца еще не разобрался

Thank you for your efforts in manufacturing this software, it's useful and beautiful. I have already recommended this software to my friend. I have only two questions, both of them are about the session.

(1)When I restart the Firefox, and click "History -> Restore previous history" in Firefox menu, tabs come back but without folders and groups, I have to import my previous session backup to solve this problem, using the "Import and merge session" option.I hope this is an automatic operation.

(2)When I start the Firefox, click the add-on's menu "Import session", and select my session backup, and horrible things have appeared, Firefox start loading the tab one by one, because amount of my tabs is huge(about 150), so it cost me 20 mins to load, and finally used 7G memory.

Can you solve these 2 problems? My Firefox's version is "Firefox Quantum 58.0.2(64-bit)". Looking forward to your reply! Thank you!

It is the most excellent tree type tab I know.

but i have suggestion.

Mistakes occur in the order of the tabs when using for a long time.
If it is difficult to suppress the occurrence of a mistake, I want a button to synchronize the order of the visible tabs and the order of the tabs recognized by the FF.

Make Tree Style Tabs looks overrated. =)

Hey, a suggestion:
What about a new config to bind groups to containers?
Then opening a new tab on that group will always open a tab of the chosen container.

After each restart the sidebar appears blank. Resetting to defaults brings it back, but again only until next browser restart. Otherwise very good experience.

Suggestions:
- reverse order option (new tabs at top)
- double click closes tab (if it's even possible in quantum)
- fogging long text instead of triple dot (looks better and cleaner)
- option to completely hide icons bar (search, settings, etc.)

This is fantastic! The features are so much better than Tree Style Tab! Why doesn't this appear as a related extension or higher in the search rankings!?

Very good extension!

Can you add Color Tabs Group? Like in Tab Kit?
Color tabs based on their parent: tabs that are related and are part of the same group have the same color

And can you add Unread/Active/Pending Tabs Color/Style too! :)
Thanks! :)

This addons very comfort use as "dynamic bookmarks" and I have a few good recommendation for improvement:
- folders must always collapsed default or make this setting for it. Folders good using as subgroups for left tabs groups;
- when actived tab located in folder, all tabs operation related with creating new tab (such as clone of tab in folder, new tab) must work only in current folder. -- New tabs creating in current folder;
- with close folder all inner tabs and subfolders must closing;
- add possibility unload all tabs for folders (in folder content menu);
- add possibility open all tabs in folder in new left tab group with deleting this folder;
- for economy memory your tabs must to makings (html code) during activating left tab group or during unfold folders/trees;
- real FF tabs must creating and linking only after activate your tabs;
- option unload tabs must close real FF tabs, but your tabs must markeds like unloads and stay in list.

Also all your tabs you can save in special folder of FF bookmarks and working from this place, where subdirs first level = groups for tab in left... Option for set base bookmark dir for addon can add to addon config.

If in FF enabled option about save tabs before close program, then with restoring tabs of browser, you addon just must merge self ungrouped tabs with other.

PS Addon is full replacement FF tabs, which must hide. Meanwhile I hide it through "userChrome.css".