Login Screen vs Lock Screen – One shouldn’t confuse the login screen with the lock screen as both are different. The login screen appears when you start up (boot into Mac) or log out of a user account whereas the lock screen appears when you lock your Mac.
While you can’t change the lock screen in Monterey on Mac, which boasts the same background image as your desktop. However, there is a workaround you can use to change the login screen on macOS Monterey. The trick involves using a third-party app, ‘Deeper’ by Titanium Software to change the background image of the login window. It can get the task done in a few clicks and without any complicated steps.
Now let’s see how to change the login screen background on your Mac running macOS Monterey 12.0 or later. The below tool supports Intel-based Mac as well as Apple Silicon Macs with an M1 chip.
How to Change the Login Screen on macOS Monterey (webtrickz.com)