It totally changed my internet browsing experience! I don't need to search where was that tab. I know where I got there from (on which page I clicked a link when new tab was opened). I know which crappy site opened a new tab without my permission. I can close whole "topic" of tabs. It is like the already existing tab-groups but evolved onto a higher level and on steroids. Problems? There are some: firefox memory limits and the fact that my browser often has 1k+ tabs opened at a time. Over a thousand - and it still works :D Don't try this on chrome or safari. Not even mentioning IE. TreeStyleTab is just great. And user experience is nice as well (Piro provided links on how to deal with UI restrictions - could be more permanent/readable but it is there.... to solve issues that he couldn't do on his own).

A great add-on. May I propose an idea? ) It would be great to have, as an option, side-tabs colored depending on tab domain.

Removed dark theme (WHY?!??!), still limited vs what it used to be before quantum.

My favorite addon! Though currently when I reopen my second window, it usually forgets the tab tree structure (un-indents all tabs). Otherwise it's perfect.

Vastly improved my tabbing experience. A must for everybody!

Tree Style Tab could be incredibly helpful, except for some bugs. I'm running Firefox on a Mac running High Sierra. The main problem is my tab trees change on their own. It seems to happen randomly, at least I haven't detected any pattern, except sometimes trees change between exiting Firefox & starting it up again.

What's very weird: I've disabled the add-on since it was becoming useless as it kept changing my trees; so I'm working without trees. This mostly works ok. However, the tabs get rearranged when exiting & restarting Firefox! I have no reason to blame this on TST, except I never had the problem before using TST!

There's also one nuisance, which might not have anything to do with TST. Often when I duplicate a tab (& I think in some other situations) the tabs are scrolled so the new tab is at the left or right edge of displayed tabs. I find this to be very annoying since I lose the context of the tab, until I manually scroll the tab list.

Dave

There is only one thing I find annoying about this extension: it automatically creates child-parent relationship between tabs which are opened from previous tabs. I'd rather have full control over tab-grouping (group them myself) than having the extension group tabs in a way I can´t even control from the options section.
Other than that, this add-on is the main reason I stick to FF, keep up the great updates!

Estoy empezando a utilizar este navegador y me ha gustado. .
De momento 4 ⭐

This new web extension is really disappointing and lacks the features of the original add-on.
I can't have both bookmarks tab open AND tree style tab open at the same time, which is a big letdown for me.
I can't close "all child tabs" at once anymore by clicking on the right click menu.
Can't close multiple tabs at once with a simple middle click on it as it always asks if I want to close multiple tabs before, which previously didn't for middle button.
When I close a tab, it tries to get the focus to the one under it (hence loading it), instead of the parent tab, and only half loads them (so that they remain buggy forever, until reload)
Also it doesn't work well with SNAP Links Plus, which, for some reason, creates useless temporary tabs with some weird indentation.
A lot of options disappeared from the add-on as well which makes it look like a watered-down rip-off of what it used to be.

EDIT :
The behavior of this add-on changed for the worst in the latest patch.
It now auto expands ALL the children and ALL their descendants upon tab selection (and not just those that were expanded before, like in previous versions)

There's no way to revert to the previous behavior and it's really annoying to have those huge FULLY expanded threes I didn't ask for.

Vraiment pratique et complet avec les addons TST. bravo

This is an awesome add-on.
Especially if you keep like 200 tabs open. It allows to organize them in a simple way.

Dear Piro, I really need your help. Last version of Firefox seems to lose internet connection when TST bar is open. I know how strange it sounds, but I confirmed that on two computers already. Having TST installed does not break anything, but if you open the sidebar, connection disappears in the next minute. But the second I close the sidebar connection restores. I will check if the issue persists if I disable other add-ons.
Please get in touch at vwa8ypaq65ts@mail.ru. I would really hate to uninstall TST.
Thanks,
Alex.

This is the best add-on on firefox. Everyone's lives would be better if they used tree-style tabs. I am a tree-style tab evangelist and the add-on is the primary reason that I use firefox.

Tab power at your finger-tips

Tree Style Tab is the main reason Firefox has been my default browser for the last several years. It is hard to believe that Firefox--nor any other browser from Chrome to Edge to Opera contains native support for these style of tabs. For any user that like to have more than 20 tabs open at a time, I find this to be essential. Absolutely the best browser feature, I just wish I could figure out a way to make a monetary donation to the developer!

Great addon! Without Tab Groups it is a lifesaver when working with lots of tabs.

All the issues have been fixed! Flat out, this extension is the main reason why I use Firefox, I can't stand Tabs on top; they are a mess when there are more then 3 open tabs! No other browser handles tabs on the side well. Chrome's similar extensions are all horrible. Edge and Vivaldi don't handle "tab children" the same way and you can't tell what tab a new tab is from if you do "Open in new Tab".

And then add in all the other addon Extensions that Piro has made for TST, it can't be beat.

I utterly fail to see why this sort of thing isn't just an option for ALL browsers. I guess it just shows how technical of user I and others that need something like TST are.