I really needed a proper tree-style extension after Tab Tree died, however I can't view any tabs. Something to do with the way it is themed no doubt. I am on 66.0.2

I had to change the theme to dark, and everything else is great! The wiki is very detailed and makes this a great tool in conjunction with tridactyl.

2025-07 更新
Firefox でも標準的に縦タブが可能になったけれども、Tree Style Tab の UX には及ばないので、まだまだ Firefox で必須の拡張機能。と言うか、Tree Style Tab を使うために Firefox を使っている。

THIS IS AN AMAZING ADDON! and its made by an amazing author, no big bugs exist, only small ones, and even they get patched almost immediately by the author, do yourself a favor, and get this extension, with just a little setup, your firefox will be 100 times better than it already is., pair it wih the tab hider extension for the ultimate pairing!

Tips for using this buggy addon:
0. Deal with it.
Ok, 1. Organize with folders or folder trees instead of tab trees when you're working with a big chunk of tabs for maximum safety. Never ever should you make blank tabs (about:blank, new tabs, or blank pages) father of other tabs. Definitely gonna f up your tree after a restart if you spot buggy behaviors with tabs before it. This one is on Firefox.
2. You may often encounter scrambled up tree structures and missing tabs that are actually hidden after a restart, so you might want to have "expand all trees" in your context menu to make them reappear, or enable expanding trees with double click. This alternative doesn't always work though.
3. Use a session restore addon that saves and restores tab metadata 'by nature', just in case everything is beyond redemption. You might already be using one anyway so this tip goes the last.

I only updated past 57 because this add-on got ported. Absolutely essential for anyone using more then a dozen of tabs and integral to my workflow.

So amazing!

It is so wonderful that I can't imagine any more words to praise it.

But there are some issues that need to be addressed.

1. Can I disable the identity TAB while using it?

2. Can the color scheme of toolbar ICONS be more similar and more user-friendly than the ICONS in firefox?

3. In the "Tree Style Tab" sidebar, can I get a clean right-click menu that only contains close, mute, lock, and the menu items I checked in the Settings, and optional or does not include submenus created by other extensions?

待ちに待ったツリー型タブのquantum版です。
非常に良好に使用していますが、自動開閉があると嬉しいです。

Just found this today, not sure what rock I've been living under that made me not find this yet. The ability to customize with the userChrome.css file is almost endless and only limited by your imagination and your google-fu. Keep up the good work!