Customizing your Mac’s lock screen and login screen used to be a complicated process that required modifying hidden system files deep within the macOS library. However, with the introduction of macOS Sonoma and Sequoia, Apple completely overhauled how these screens operate.
If you want to change the image you see when you wake up or turn on your Mac, you need to understand the difference between the “Lock Screen” and the “Login Screen,” as modern macOS treats them entirely differently.
How to Change the Lock Screen Background
The Lock Screen is the screen you see when you wake your Mac from sleep, or when you lock your screen while stepping away from your desk. In macOS Sonoma and later, Apple simplified this entirely: the Lock Screen now perfectly mirrors your Desktop Wallpaper.
To change your Lock Screen, you simply need to change your desktop background.
- Click the Apple Logo in the top left corner of your screen.
- Select System Settings.
- Scroll down the left sidebar and click on Wallpaper.
- Select an image, or click Add Photo to upload your own custom image.
If you select one of Apple’s new “Dynamic Landscapes” or “Cityscapes,” the video will play in slow motion on your Lock Screen, and gracefully come to a stop the moment you type in your password and enter the desktop.
Understanding the “Login Screen” Limitations
The Login Screen is the screen you see immediately after you turn your Mac on from a complete shutdown, or after a full restart.
You cannot set a custom image for the initial Login Screen.
This is a deliberate security feature. If you have FileVault disk encryption enabled (which Apple strongly recommends), your Mac’s hard drive is completely locked and encrypted when it is powered off. When you turn the Mac on, the computer has no access to your personal files, including your custom wallpaper image.
Therefore, the initial boot screen will always display the default system wallpaper for whichever version of macOS you are running. Only after you type in your password does the Mac decrypt your hard drive, load your personal profile, and display your custom Lock Screen and Desktop wallpapers.
Beware of Old Tutorials
If you search the internet, you will find older tutorials suggesting that you can change the login screen by turning off FileVault, or by replacing a specific lockscreen.png file inside the /Library/Caches/Desktop Pictures/ directory.
Do not attempt this on modern Macs.
- Turning off FileVault removes the encryption from your hard drive, leaving your personal data vulnerable if your Mac is stolen.
- Modern macOS utilizes a Signed System Volume (SSV) which completely locks down system files. Trying to hack your way into the core directory to replace image files will likely fail, and can cause severe system instability during future macOS updates.
For the sake of your Mac’s security, accept the default system wallpaper for the 10 seconds it takes to boot, and enjoy your custom wallpaper everywhere else.