Firefox tabs in the title bar

Question

Is it possible to put the Firefox tabs on the title bar when using KDE on Debian stable, similar to what happens on Windows?

There's an option on about:config, browser.tabs.tabsintitlebar that enables that on the current Firefox window but it stops doing that when closed or other windows are open.

Answer 1

You don't need to mess with about:config for that. Open up the hamburger menu (three horizontal lines) to the right of the URL bar and click on Customize. There's a checkbox at the bottom left labeled "Title Bar" that you can uncheck.

Edit:
In order get Firefox from Debian Unstable while still using the Stable repository for all of your other packages, add the following to your /etc/apt/sources.list:
deb https://deb.debian.org/debian/ unstable main contrib non-free

Next, add the following to etc/apt/preferences (create the file if it doesn't already exist):

Package: *
Pin: release a=stable
Pin-Priority: 1000

Package: *
Pin: release a=unstable
Pin-Priority: 2

Package: firefox
Pin: release a=unstable
Pin-Priority: 1001

Package: libfontconfig1
Pin: release a=unstable
Pin-Priority: 1001

Package: fontconfig-config
Pin: release a=unstable
Pin-Priority: 1001

Package: libnss3
Pin: release a=unstable
Pin-Priority: 1001

Then run sudo apt update && sudo apt install firefox

Answer 2

I am using Firefox on Garuda with Plasma desktop. It tried to follow the accepted answer but in my case, it's slightly different but not intuitive.

Quick method

Right-click on the down arrow in the upper right corner of the window.

To be honest, you can right-click anywhere on the navigation bar which contains the search bar and extension symbols. However right-clicking on the text field bars will provide a different context menu.

In that context menu, just enable the "menu bar" checkbox.

The long way

Alternatively, the way described by Pierce Griffiths, you can do following.

First click on the common Hamburger menu.

Then click on "more tools".

The top option is the "customize toolbar" which contains the desired option.

(Well, if you paid attention to the context menu picture before, you might have noticed, can also select "customize toolbar" there, instead of immediately clicking on "menu bar".)

There, in the bottom left corner, you can also find it as a checkbox named "title bar".

conclusion

Just in case, your version doesn't support a certain way of showing the menu bar, I tried to show multiple ways to enable (or disable) the menu bar.