Awesome.

One of the most useful extension and the number one reason why I use Firefox.

Really nice Add-On, especially for the fact that I can edit the CSS inside the settings.
Just one thing: Would it be possible to add an option to set the animation speed or transition time?

Using it for a long time now... I love it... Firefox should have vertical tabs by default, its way more intuitive to scroll up/down than to move the tablist left/right, and its more productive since pages are vertical usually and vertical space is more precious nowadays

The tree feature is the best grouping/tracking of set of pages

The only thing this addon lack is the coloring of the tabs, would love to see that feature in a future release

To change the size of the tabs do:
/* Change tab height */
.tab {
height: 24px;
}

Following the message of XenGeek
I used this code to remove Tabs keeping the title bar.

/* Remove horizontal tabs */
#tabbrowser-tabs {
visibility: hidden;
margin-top: 40px;
margin-bottom: -50px;
}

/* Remove sidebar header */
#sidebar-header {
visibility: collapse;
}

Anyway this add-on is very good, I don't understand why this tree tab menu is not a standard in Firefox. Saved me a lot of time and energy !

Thanks a lot !

Extension is very handy. But last update asks for accessing all my web data. Why??? I'm not installing it for now cause there is no justification anywhere why this permission has been requested.

To add on to Anonymous user fc7bf5's comment. If you want to get rid of the Horizontal Tabs and the Title Bar for the sidebar simply add the following in your Firefox Profile. This is not the Local AppData one, but the Roaming one which is normally found at: %UserProfile%\Appdata\Roaming\Mozilla\Firefox\Profiles

You will have a profile folder here, maybe more if you utilize multiple profiles in Firefox. Once you pin-point yours you simply need to add a new folder called "Chrome" in your profile folder and create a new text file "userChrome.css" make sure it is a css file and not a txt. you may have to google how to change file extensions by revealing them in Windows. The contents of that file should contain one or both of the following segments depending on what you want.

/* Contributed by Anonymous user 099626's */
/* Remove horizontal tabs */
#tabbrowser-tabs {
visibility: collapse;
}

/* Remove sidebar header */
#sidebar-header {
visibility: collapse;
}

Once this is done you will have to restart FireFox. Depending on your theme in FireFox you may notice you can't see the windows control buttons in the upper right. To fix this simply go to the "Customize..." menu and check the "Title Bar" option then click done.

ps. I've noticed some FireFox menu's don't take the removal of the Horizontal Tabs into account due to it not being a build in option. With this in mind option screens like "Customize..." may take over your full screen including the TreeStyle Tabs. If this happens simply look for another way to close the screen, which should be provided.

pps. TreeStyle Tabs is a fantastic app that I've used for years, I've slowly started moving to Chrome because of the noticeable speed difference and the large amount of multitasking I have to do daily. I am excited to see if FireFox Quantum can live up to the speed it boasts. That being said...

Happy Tab Hoarding! :D

Tried to make the new version work with 57, but it doesn't. Reverted to 56.02 to resume using the old add-on, which does work.

Why is Mozilla killing off its add-on ecosystem?

It works! And it's a tree! And there are many and sensible config options! And it integrates with containers!! Wooohooo!!!

You have to manually disable the horizontal tabbar at this moment. This is a limitation of the webextension api, not something this extension can currently do something about. But once that's possible, it'll get the final star ;-)

Kein Ersatz für Tab Mix Plus aber wenigstens läuft es im neuen Firefox 57 (Quantum)

Why are so much permission required lately? It's asking right now for every data everywhere and it's kind of freaking me out..
I find this extension very usefull thought

Love the extension. Please find a way to remove the tab bar at the top!

Thanks to Anonymous user fc7bf5 for fixing the problem to remove the tab bar at the top!

With this fix 5 stars. Strange that the creator of this usefull extension didn't solve this problem.

Works well. Just need the top bar of tabs to be hidden.

For anyone having trouble with the horizontal tabs not hiding, Anonymous user 099626's advice worked for me. Create a folder chrome/ in your firefox profile and then in that directory a userChrome.css file containing the following rules

/* Remove horizontal tabs */
#tabbrowser-tabs {
visibility: collapse;
}

If you want to get rid of the sidebar header, add this to the file:

/* Remove sidebar header */
#sidebar-header {
visibility: collapse;
}

You will have to restart Firefox to enact the changes.

Cannot remove tab bar on top anymore.

just got it