The lock screen background option was removed from settings since Ubuntu 20.04. Now, it uses desktop wallpaper with blur effect as the background for the lock screen.

For those who still want to change the lock screen background, then there’s an extension that supports GNOME from version 3.26 to 47. Meaning all current Ubuntu releases, Fedora, and other Linux with GNOME are supported.

NOTE: This tutorial only works for the default GNOME Desktop!

Option 1: Use Extension Manager

For Ubuntu 22.04, Ubuntu 24.04 and higher, there’s a popular “Extension Manager” app available in system repository for install and manage extensions in default GNOME desktop.

1. First, launch App Center or Ubuntu Software. Then, search for and install the “Extension Manager” app:

Install Extension Manager in Ubuntu Software/App Center

2. Then, launch the “Extension Manager” app, navigate to “Browse” tab. Finally, search & install the “lock screen background” extension.

Tips: Try switching the filter if it does not show you that extension. Or, use Option 2 to install it using web browser.

3. Once installed, switch back to “Install” tab, and click on the setting icon for that extension. Finally, click on “Browse” button in pop-up dialog and choose an image file for the login background.

Option 2: Use web browser

Extension Manager is not available in system repository for old Ubuntu 20.04 and earlier. In the case, you may use your web browser to install the extension.

1.) Open terminal by pressing Ctrl+Alt+T on keyboard. When it opens, run command to install the agent package as well as Gnome Extensions app:

sudo apt install chrome-gnome-shell gnome-shell-extension-prefs

2.) Then open your web browser (e.g., Firefox), and go to the link button page:

Finally, use the ON/OFF toggle to install the extension.

Don’t see the toggle switch? Try clicking the link text “click here to install browser extension” and follow the pop-ups to install the browser extension. Then, refresh the page.

3.) Finally, launch GNOME Extensions app or Gnome Tweaks > Extensions, go to the extension settings page, and finally set a picture for lock screen background.

That’s it. Enjoy!