Very, very round.
Firefox version 157 (Nova) “refreshes” the interface by taking the very, very round corners found in macOS Tahoe and applying them across everything in the browser.
I thought I remembered reading it would come with a control to let you set the roundness of the corners of various elements, because, as mentioned, they are very, very round. But I appear to have misremembered.
There is a way to turn the roundness off, described below. The option may disappear in the future, but it’s there, for now.
Revert Firefox to pre-Nova/157 look
- Enter
about:configin the address bar and click the button to proceed if you get a warning. - Search for nova.
- Click on the option
browser.nova.enabledand set it to false. - Restart Firefox (may not be necessary).
- Enjoy the pre-157 look.
The full manual control version
This keeps Nova, but lets you set how round various UI elements will be. I found it created some visual weirdness, but that might just be on my system.
- Enter
about:supportin the address bar. - Under Application Basics find Profile Folder and click the Open Folder button.
- Create a folder in your profile folder called Chrome.
- Create a file in the Chrome folder called userChrome.css.
- Add this to the user.css file, save it and restart Firefox:
/* Force square corners on all Firefox UI elements */
* {
border-radius: 0px !important;
}
Set the px value to 0 for a fully sharp-edged experience. If you want a little roundness, adjust the value to taste. Somewhere around 4px-6px is close to pre-Nova.


