Normally, when you start up your Mac, the login screen will show your usual desktop background. Change desktop background in System Preferences, and it will change your login screen and your lock screen wallpaper.
But what if you want to customize your login screen? And what other customisations can you add to your lock screen and login screen?
In this guide, we’ll show you how to change your wallpapers, as well as icons and more.
Before we start
When you’re creating new images to use as your Mac’s login and lock screen pictures, you can easily end up making duplicates too. These take up space unnecessarily on your Mac’s system drive. With MacKeeper, you can find and remove duplicate images and files quickly and easily.
- In MacKeeper, select Duplicates Finder
- Click Start scan
- When the scan is finished, select anything you want to delete, and click Remove selected
MacKeeper will find not only exact copies, but also images that are similar. Plus it has many other features, including real-time antivirus, a VPN client and more. Try out today to see how it can help you. You get one completely free try of each of its many tools.
How to prepare your Mac login image
Before you can change your Mac’s login background, you need to make sure it’s the right format and size. You can do that with most photo editing software, but the macOS Preview app will do it just fine.
Here’s how to prepare your login screen wallpaper with Preview:
1. Click the Apple logo in the top left corner of your screen and select About This Mac

2. Open the Display tab and take note of your Mac’s screen resolution

3. Open the picture you want to resize using the Preview app

4. Click Tools from the top panel and select Adjust Size

5. Change the resolution of your photo to match your Mac’s screen size, then click OK

6. Click File from the top panel and select Save

7. If your image isn’t in PNG, you’ll need to save a new version. Select File > Export

8. Select PNG as the format, and click Save

9. Now rename your image to lockscreen.png

How to change your Mac’s login screen image
Once you’ve prepared your new login background image, you need to put it in the right folder on your Mac. You’ll see it the next time you log in.
Just follow these steps to change your Mac’s login wallpaper:
1. In Finder, select Go > Go to Folder from the menu bar
2. Copy and paste /Library/Caches/Desktop Pictures in the address bar, then press Enter

3. In the Desktop Pictures folder, you’ll see one or a few folders. These are named after user UUIDs. Open your folder and you should see a lockscreen.png file

4. Replace it with your own image, also called lockscreen.png. Enter your username and password if prompted

5. Restart your Mac to see your login wallpaper

What to do if you don’t see a folder in Desktop Pictures
If there’s no UUID folder in the Desktop Pictures folder on your Mac, you’ll need to manually create one.
Here’s how to set up a UUID folder on your Mac:
1. Go to System Preferences > Users & Groups

2. Click the lock icon and type in your admin password

3. Right-click on your user name, and choose Advanced Options

4. Next, copy the UUID of your User ID

5. Go to the /Library/Caches/Desktop Pictures folder, and create a new folder with your UUID as its name. Enter your username and password if asked

6. You can now copy your lockscreen.png into this folder to change your login wallpaper
How to change your lock screen wallpaper
Your lock screen is different to your login screen. You’ll see it when you wake your Mac up from sleep. When you change your login screen background, your lock screen will stay the same. To change your lock screen, you simply have to change your Mac’s desktop background.
Here’s how to set your Mac’s lock screen:
1. Open System Preferences
2. Choose Desktop & Screen Saver

3. Choose an image from the included selection

4. To choose an image from somewhere else on your Mac, click the plus button

How to add a message to your Mac lock screen and login screen
Using System Preferences, you can set a written message that appears on both your login screen and lock screen. You could, for example, add your contact details, which would be useful if you lost your MacBook.
You can add a message to the login and lock screen by following these easy steps:
1. Go to System Preferences, and open Security & Privacy

2. In the General tab, click the lock icon, and enter your password

3. Check the box next to Show a message when the screen is locked

4. Next, click on Set Lock Message

5. Write your message and click OK

6. That’s it! Your message is now set

Change user icons on your lock screen and login screen
Every user on your Mac will have a different icon or avatar, and macOS comes with a good selection to choose from. But you can also add your own, such as a photo of yourself. You can even add a shot from your webcam.
Here’s how to set your own user icons on your Mac:
1. Open System Preferences, and click Users & Groups
2. Hover over your user icon and click Edit

3. Choose your new image or just take a new photo using your Mac’s webcam

4. Click Save
5. Your new icon will appear on your Mac’s lock screen and login screen

How to make your login screen the same as your desktop background again
When you change your Mac’s desktop background in System Preferences, it will also change your lock screen and login background. So if you’ve set a custom login screen picture, this will be overwritten.
For that reason, it’s a good idea to keep a copy of your custom login wallpaper, so you can restore to the Desktop Pictures folder if it gets overwritten.
Read more: