u/Tomhero200

(Marked as Discussion since I didn't find any better flair)

I found a way to get the compact mode from nova to the old UI.

Requirements: A version of Firefox with Nova (157+) (Librewolf is also supported!)

What to do:

1. Enable Nova, if not done already (browser.nova.enabled in about:config set to true, For Librewolf: Settings > Appearance > Enable the Nova Redesign)
2. Go to Settings > Appearance and set "Window Density" to "Compact"
3. Disable Nova in about:config (Librewolf users can use the settings option mentioned above)

You now got compact mode in the old UI!

(Firefox devs, please don't 'fix' this, thank you!)