Setting browser.tabs.tabmanager.enabled to false still works in the old way, meaning that the button is hidden by default and is shown if the number of open tabs exceeds a limit.

Using #alltabs-button { display: none !important; } in userChrome.css also should still work.

It is not that difficult to create userChrome.css if you have never used it, so you can check that you created userChrome.css properly.

The first step is to open the "Help -> Troubleshooting Information" page and find the button to access the profile folder with the random name (xxxxxxxx.default-release).

• https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox

You can find the button to go to the profile folder under the "Application Basics" section as "Profile Folder -> Open Folder". If you click this button then you open the profile folder in the Windows File Explorer. You need to create a folder with the name chrome in the profile folder with the random name (name is all lowercase). In the chrome folder you need to create a plain text file with the name userChrome.css (name is case sensitive). In this userChrome.css text file you paste the text posted. On Mac you can use the TextEdit utility to create the userChrome.css file as a plain text file.

In Windows saving the file is usually the only time things get more complicated because Windows can silently add a .txt or .css file extension and you end up with a file like userChrome.css.txt or userChrome.css.css. To avoid this, you need to make sure to select "All files" in the "Save File" dialog in the text editor.

You need to close (Quit/Exit) and restart Firefox when you create or modify the userChrome.css file.

More info about userChrome.css/userContent.css in case you are not familiar:

• https://www.userchrome.org/what-is-userchrome-css.html
• https://www.userchrome.org/how-create-userchrome-css.html
• https://www.userchrome.org/firefox-changes-userchrome-css.html

You need to set this pref to true in about:config to enable userChrome.css and userContent.css in Firefox 69+.

• about:config => toolkit.legacyUserProfileCustomizations.stylesheets => true
• https://support.mozilla.org/en-US/kb/about-config-editor-firefox

Although setting browser.tabs.tabmanager.enabled to false in about:config still does not work (tested multiple times between browser and system restarts), repeating cor-el's steps to access my profile folder uncovered my mistake. I originally went to about:profiles and opened the Local path of my profile folder instead of the Roaming path, and created the userChrome.css file there.

After moving the chrome folder I created from Local to Roaming, the .css file began working.

For over 8 years this has been a consistent issue between users. And in 8 years absolutely NOTHING has been done to remedy the issue other than telling people to use about:config and chrome scripts. browser.tabs.tabmanager.enabled DOES NOT WORK, stop suggesting it.

"It is not that difficult to create userChrome.css if you have never used it, so you can check that you created userChrome.css properly."

^ Maybe not difficult for the % of people that know and feel comfortable doing it. But what about the other % that just want to remove it? Or go back to when it used to DISAPPEAR when not needed and show up when there are tabs overfilling the top bar? It's extremely easy to just setup an and/or. So much has just went downhill with this project in the last so many years. Are people no longer proficient in coding? Seems like if it can't be copied and pasted from someone else's work, it doesn't get fixed or brought into fruition anymore. This has been happening across the whole board of companies, just everything going to crap. Fake it til you make it doesn't and shouldn't apply to coding. Do better.

Although setting browser.tabs.tabmanager.enabled to false in about:config still does not work (tested multiple times between browser and system restarts), repeating cor-el's steps to access my profile folder uncovered my mistake. I originally went to about:profiles and opened the Local path of my profile folder instead of the Roaming path, and created the userChrome.css file there. After moving the chrome folder I created from Local to Roaming, the .css file began working.

https://bugzilla.mozilla.org/show_bug.cgi?id=1916622

Here's the best explanation I've found about why they made it hard to remove: https://www.quippd.com/writing/2024/10/02/the-reason-the-list-all-tabs-button-is-permanent-is-because-of-firefox-view.html

I did try the above solutions, and after scrutinizing and following through to the bottom, it did work. There are clearer instructions of the same process out there, on Reddit and elsewhere.

Unsure why "list all tabs" cannot be removed via customization and/or about:config, but let's put that aside for a second. (Why force css?)

@cor-el mentioned "Setting browser.tabs.tabmanager.enabled to false still works in the old way, meaning that the button is hidden by default and is shown if the number of open tabs exceeds a limit."

I'm seeing the button with only a single tab opened. Should I log a bug?

Setting browser.tabs.tabmanager.enabled to false doesn't work. The second method DID work for me, after I finished it off with toolkit.legacyUserProfileCustomizations.stylesheets to True

A clearer, step-by-step, screen-shotted version of this CSS solution can be found here, for us less tech savvy users: https://windowsreport.com/firefox-remove-list-all-tabs-button/

The browser.tabs.tabmanager.enabled pref is no longer supported in Firefox 131+ versions, now you can only do this by using CSS code in userChrome.css.