Do you wish all apps you use on Ubuntu 22.04 used rounded corners at the bottom of windows, the same way all modern GTK4/libadwaita apps do?

It’s a visual discrepancy that (for those who notice such things) sticks out a mile once you’re aware of it. Older GTK 3 apps (like GNOME Terminal and Shotwell) and Electron apps (like VSCode and Discord) are among those using squared bottom corners.

But you can do something about it using—of course—a GNOME Shell extension!

Aptly titled, the Rounded Window Corners GNOME extension attempts to “…add rounded corners for all windows”.

Having tried it out I can say that it works brilliantly well with GTK 3 apps (as pictured). It also goes out of its way to apply rounded bottom corners to other common toolkits, including Electron apps like VSCode and Spotify.

Animated gif showing ubuntu 22.04 using the rounded window corners GNOME extension
The effect in action – subtle, but shapely

So how does it work?

The developer of this extension makes use of a shader from Mutter to adjust the appearance of window corners. They also add that TypeScript support for GJS (what powers GNOME Shell extensions) is powered by gi.ts — something I hadn’t heard of before, so that’s neat.

I’ve (sort of) written about a rounded mutter effort before. Alas, that one involved building and installing a patched version of Mutter, so not exactly easy to “undo” if it starts causing issues.

This is a simple GNOME extension. If you get bored of it, or find it doesn’t work with the apps you were trying to force rounded corners on, you can easily turn it off.

The extension boasts:

  • Support for GNOME 40 through 44
  • Define a border radius, border, and padding
  • Customise drop shadow for rounded corner windows
  • Add apps to an exclusion list to skip rounding them
  • Option to not apply custom radius to GTK4/libadwaita apps

One thing I have noticed while using this is drop shadows on app windows appear rather flat towards the top. This affects both unfocused and focused apps and is most noticeable when several apps are overlapping each other.

But — and this really impresses me — you can customise these drop-shadows via an interactive settings dialog, for both focused and unfocused apps. The amount of controls is vast with options to tweak opacity, spread, blur, and more:

screenshot of rounded window corners gnome shell extension's settings dialogs

I recommend you take a screenshot of the extension’s default values before you start adjusting sliders as there’s no one-click “reset” option (at the time of writing). Of course, disabling the extension will disable the effect with no unexpected leftovers or quirks.

Other options include an exclusion list. Apps added to this will not be affected. And there’s a toggle to force the extension to apply your custom settings to GTK4/libadwaita apps too – they already have native rounded corners though, so maybe don’t!

Try it Out

The Rounded Window Corners GNOME extension offers a quick and easy way to force all apps on your desktop to use rounded window corners. Advanced controls over radius shape, opacity, and drop-shadow let you fine-tune things further.

You can install the extension from the GNOME extension website. File bugs or contribute code via the GitHub project page.

Give a whirl and let me know what you think of it down in the comments — and remember: finding, installing, managing, and removing GNOME extensions is much, much easier with the Extension Manager app, available from Flathub or in the Ubuntu 22.04 LTS repos.