Introduction
The default Mac login screen wallpaper is a blurred version of your desktop background, but you can replace it with any custom image you choose. This involves replacing a system file deep in macOS, which is more involved than a normal wallpaper change—but entirely safe if you follow the right steps and back up the original file first.
This guide walks through the replacement process for both Apple Silicon and Intel Macs. For standard wallpaper changes, see our how to change wallpaper on a Mac guide . For multi‑display setups, our Mac wallpaper multiple displays guide covers per‑screen customization.
Where the Login Screen Wallpaper Lives
The Mac login screen wallpaper file is stored in a system directory. The exact path is:
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/Library/Caches/com.apple.desktop.admin.png
This file is a PNG image that macOS generates automatically based on your current desktop wallpaper. When you change your desktop background, macOS updates this file with a blurred version of that image. To use a custom image instead, you replace this file with your own.
How to Replace the Login Screen Wallpaper
Step 1: Prepare Your Image
Choose the image you want to use. It should be the same resolution as your display for the best results (e.g., 3024×1964 for a 14‑inch MacBook Pro). Rename it to com.apple.desktop.admin.png.
Step 2: Back Up the Original File
Open Terminal and run:
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sudo cp /Library/Caches/com.apple.desktop.admin.png ~/Desktop/original-login-wallpaper.png
This saves the original login wallpaper to your desktop. If anything goes wrong, you can restore it.
Step 3: Replace the File
In Terminal, run:
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sudo cp /path/to/your/image.png /Library/Caches/com.apple.desktop.admin.png
Replace /path/to/your/image.png with the actual location of your custom image. You can also drag the file from Finder into Terminal to automatically insert its path. Enter your administrator password when prompted.
Step 4: Restart or Log Out
The login screen wallpaper updates after you restart your Mac or log out and return to the login screen. You will see your custom image instead of the default blurred desktop.
How to Restore the Original Login Wallpaper
If you want to revert to the default login screen wallpaper, copy your backup file back to the original location:
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sudo cp ~/Desktop/original-login-wallpaper.png /Library/Caches/com.apple.desktop.admin.png
Then restart or log out. The default blurred wallpaper returns.
Troubleshooting: What to Do If It Doesn’t Work
Problem: The login screen still shows the old wallpaper after replacement.
Make sure you restarted or logged out completely. Simply locking the screen (Control + Command + Q) does not reload the wallpaper file. A full logout or restart is required.
Problem: My custom image appears distorted.
The image resolution does not match your display’s native resolution. Resize your image to exactly match your screen dimensions.
Problem: Terminal says “Operation not permitted.”
You may need to grant Full Disk Access to Terminal. Go to System Settings > Privacy & Security > Full Disk Access and add Terminal to the list.
Important: macOS Updates May Reset the Wallpaper
When you install a major macOS update, the system may replace your custom login screen wallpaper with the default. After each major update, repeat the replacement process. Keeping a copy of your custom image and the backup file makes this a two‑minute fix.
Frequently Asked Questions
Does this method work on Apple Silicon Macs?
Yes, the process is identical on Apple Silicon and Intel Macs.
Will changing the login wallpaper void my warranty?
No. You are replacing a cached image file, not modifying core system software. This is safe and reversible.
Can I use a dynamic or live wallpaper on the login screen?
No. The login screen wallpaper must be a static PNG image. Dynamic and live wallpapers are not supported at the lock screen.