robni7 / loginwallchanger

An AppleScript applet to help you install a custom login window wallpaper on macOS Catalina (& now Big Sur).

CatalinaLoginWallChanger

This applet will help you install a custom login window wallpaper. This is done by renaming the standard Catalina wallpaper to Catalina-dynamic and replacing it by an image file of your choice.

Note: A side effect of this method is that the chosen wallpaper will also be the default wallpaper for new users.

On Catalina, you will need to disable System Integrity Protection in order for this applet to work.
On Big Sur, you will need to disable System Integrity Protection and Sealed System Volume in order for this applet to work. Please make sure you are also aware of the implications this may have on your system.

Use at your own risk. Be sure to have a back-up of your system before proceeding.

Version 1.5, by robni7. See code.txt for the source AppleScript code.

How to use:
Dowload the files by using the green download button -> Download ZIP or find the newest package in the right sidebar. After you have unpacked the ZIP, launch CatalinaLoginWallChanger.app. You may have to control-click and choose "open" to open the applet.