I am confused by what you mean but you could follow images below and customize Firefox UI to your liking.

Hi iglicious, could you check the Customize tab? Look for a checkbox in the lower left corner for Title bar and see whether you can turn it off there:

Customize Firefox controls, buttons and toolbars

If that doesn't exist, you could try this approach (the preference that the checkbox controls):

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste title and pause while the list is filtered

(3) If the browser.tabs.drawInTitlebar preference is currently false, double-click it to flip the value to true

Note that the Firefox version from the Ubuntu repositories that you appear to be using might behave differently and might not support client-side-decoration.

Try the Firefox version from the official Mozilla server if you currently use a version from the repositories of your Linux distribution.

• https://www.mozilla.org/en-US/firefox/all/

Dear jscher2000,

Your solution works. Thanks for sharing it with us.