You can customize your login screen on your Mac. This article describes how you can change your macOS Big Sur login screen to display any image you want when your Mac turns on. Here is how:
The login screen is where you enter your password.
See also:
- macOS Catalina: How To Change The Login Screen Background
- How to Change the Login Screen Background on macOS Mojave
How to change the Big Sur login screen
1. On your Mac, in the Finder, choose Go > Go to Folder.
2. Type the following pathname and click Go.
/Library/Caches/Desktop Pictures
3. In this folder, you will see one or more folders. The folders are named after the name of the user’s UUIDs. Open this folder and you will see a file named “lockscreen.png”. Please note that if you do not have a folder named Desktop Pictures, create this folder inside the Caches folder. Then you will need to create a folder with UUID value as name inside the Desktop Pictures folder (see below).
Furthermore, If Desktop Pictures folder exists but if you do not see a folder inside the Desktop Pictures folder, you will again need to create one UUID value as name. Here is how.
See also: How To Screenshot (Print Screen) And Record Screen On Your Mac
A. On your Mac, open System Preferences and click Users & Groups.
B. Click the Lock icon and enter your passcode to unlock this section.
C. Right click (or control-click) on user name and select “Advanced Options…”.
D. Now, copy the UUID of your User-ID.
E. Now go to the “/Library/Caches/Desktop Pictures” folder again. And create a new folder. The name of this folder should be your UUID.
F. Now right click this new folder and click Get Info. Make sure that your computer has Write privileges. Grant permissions Read & Write to user, admin, everyone.
See also: Mac: How To Troubleshoot Screen Flickering
4. Now select the current lockscreen.png image (if you have this image in the folder) and rename it old-lockscreen.png.
5. Now find an image or photo that you want to use as your login screen background and drag-and-drop the image (name it lockscreen.png) into the open folder.
Now restart your Mac and you are done.
See also:
Found the answer, apparently /System/Library/Desttop Pictures/Big Sur Graphi.heic is where the login screen background loads from.
To change it:-
boot into the recovery mode
open terminal
type: csrutil disable
press enter
type: mount -uw / /dev/diskXsY <–
Attention!!! X=your Big Sur disk from 'diskutil list'
Y=your Big Sur disk slice
Now the Big Sur volume should be writable
6. Reboot normaly
7. name your own grafic image as Big Sur Graphic.heic
8. copy your own grafic image in to Macintosh HD
9. reboot into the recovery mode
10. open terminal
11. type: mount -uw / /dev/diskXsY <–
Attention!!!! X=your Big Sur disk from 'diskutil list'
Y=your Big Sur disk slice
12. type: cd /
13. type: cd /Volumes/Macintosh\ HD/System/Library/Desktop\ Pictures
14. type: mv /Volumes/Macintosh\ HD/System/Library/Desktop\ Pictures/Big\ Sur\ Graphic.heic /Volumes/Macintosh\ HD/System/Library/Desktop\ Pictures/Big\ Sur\ Graphic.heic.orig
15. type: mv /Volumes/Macintosh\ HD/Big\ Sur\ Graphic.heic /Volumes/Macintosh\ HD/System/Library/Desktop\ Pictures/Big\ Sur\ Graphic.heic
16. Reboot
Now you have your new login background
17. Reboot into the recovery mode
18. open terminal
19. type: csrutil enable
20. press enter
21. reboot e voilá
¯\_(ツ)_/¯
I used your setps above and added some photos of my own to the folder , choosing one as “login.png” and renaming the other “old-login.png” >I have two users one of them amin, one standard. When I reboot standard login screen comes up as changed (new) login BUT if I logout/or choose not to login as standard account the login screen revertys to old-login.png THAT DREADFUL ORANGE WAVY THING! Why?
I’ve had an odd experience with my new Mac mini M1 on Big Sur. With no action on my part whatsoever, the Mac just picked a photo from my Photos library as my log-in screen photo. Fortunately it’s of my husband and our dog, but I didn’t do it!
The only thing I can think of as perhaps affecting this is my efforts to get the actual Desktop to randomly cycle. The checkbox was grey no matter which included Desktop pic I selected. I was able to highlight my own Photos, pick an album, and suddenly the checkbox appeared. When I picked a the Favorites folder, it cycled fine. Went back to the stock pics, and this time the checkbox stayed checked. Mac has been cycling the Desktop just fine. First restart, and the pic of my husband and dog appear.
Does anybody have any idea how this happened?