Earlier quoted context omitted.
Tree Style Tabs is a popular one. Though none can take away the Tabs in title bar without manually installed CSS hacks.
$ cat userChrome.css /* Mozilla chrome (UI) styling */ /* Hide tabs bar * * Fri Nov 17 12:23:47 CST 2017 * https://superuser.com/questions/1268732/how-to-hide-tab-bar-tabstrip-in-firefox-57-quantum * https://www.ghacks.net/2017/09/27/tree-style-tab-is-a-webextension-now/ */ #tabbrowser-tabs { visibility: collapse !important; }
``` #main-window:not([customizing]):not([tabsintitlebar="true"]) #toolbar-menubar[inactive="true"] + #TabsToolbar { visibility: collapse !important; } ```
This snippet shows tabs when in "customize" mode, so you can access elements from addons placed on the tab bar by default. It also shows tabs when the menubar is showing: tap alt to peek, enable menubar to have vanilla access to tabs again. Finally, if you use the setting "tabs in titlebar", tabs are not disabled.
Doing it this way enforces sensible behavior and gives you escape hatches that don't require editing CSS and restarting the browser.