The fastest way to change your Mac background

Open System Settings, click Wallpaper in the sidebar, then pick a new image from the gallery or upload your own. The change takes effect immediately on your desktop and lock screen. The whole process takes under a minute.

If you want to use a photo from your own files instead of Apple's built-in images, you can drag it directly into the wallpaper picker, or browse to it using the file selector. Mac remembers your choice and keeps it until you change it again.

Key Takeaways

  • System Settings > Wallpaper is the only place you need to go — there is no separate app or preference pane.
  • You can pick from Apple's gallery of images, or upload any photo from your computer in JPEG, PNG, HEIF, or TIFF format.
  • The same image can appear on your desktop and lock screen, or you can set them to different pictures.
  • Once you choose a background, it stays until you manually change it again — Mac does not rotate through images on its own unless you turn on a slideshow.

How to pick a background from Apple's gallery

Click the Apple menu in the top-left corner of your screen, then select System Settings. In the sidebar on the left, scroll down and click Wallpaper. A panel will open showing categories like Collections, Nature, Abstracts, and Solid Colors.

Click any category to see the images inside it. When you find one you like, click it once to preview it on your desktop. If you want to keep it, the change is automatic — you do not need to click a save button. If you want to try another image, just click a different one.

How to use your own photo as a background

Open System Settings and go to Wallpaper as described above. At the bottom of the window, you will see a folder icon or a plus sign. Click it to open a file browser. Navigate to the folder where your photo is stored, select it, and click Open.

Your photo will appear in the Wallpaper panel. Click it to set it as your background. If the image is very large or very small, Mac will automatically fit it to your screen. You can also drag a photo directly from Finder into the Wallpaper window without using the file browser.

Setting different backgrounds for desktop and lock screen

In the Wallpaper panel, you will see two preview areas — one labeled Desktop and one labeled Lock Screen. By default, the same image appears in both. To change just one of them, click the preview area you want to edit, then pick a new image from the gallery or upload a different photo.

This is useful if you want a professional image on your lock screen but something more personal on your desktop, or vice versa. Each setting is independent, so changing one does not affect the other.

How to set up a slideshow background

If you want Mac to rotate through multiple images instead of showing a single static background, open Wallpaper in System Settings and look for a Slideshow option. Click it, then choose a folder containing the photos you want to cycle through.

You can set how often the image changes — options usually range from every 5 seconds to every hour. The slideshow runs on both your desktop and lock screen unless you configure them separately. To turn off the slideshow, go back to Wallpaper and select a single image instead.

Troubleshooting background changes that do not stick

If you change your background but it reverts to the previous image after you restart, check whether another user account on your Mac is overriding the setting. Each user account has its own background preference, so make sure you are logged into the account where you made the change.

If you are using a work Mac managed by your employer, your organization may have locked the wallpaper setting so employees cannot change it. Contact your IT department to ask whether the restriction can be lifted. If you uploaded a photo and it disappeared, the file may have been moved or deleted — try uploading it again from its current location.

Image formats Mac accepts for custom backgrounds

Mac can use photos in JPEG, PNG, HEIF, and TIFF formats as backgrounds. Most photos from your camera or phone are already in one of these formats. If you have an image in a different format like BMP or GIF, you can open it in Preview, go to File > Export, and save it as a PNG or JPEG before uploading it to Wallpaper.

There is no size limit, but very large files may take a moment to load. Mac automatically scales the image to fit your screen, so you do not need to resize it yourself beforehand. If the image looks blurry or stretched after you set it, try a higher-resolution version of the same photo.

Frequently Asked Questions

Can I set a different background for each desktop space?

No. Mac applies the same background to all your desktop spaces at once. However, you can use a third-party app from the App Store to assign different wallpapers to different spaces if you need that level of control.

What happens to my background if I update macOS?

Your custom background choice is preserved during a macOS update. If you were using one of Apple's built-in images, it will remain the same. You do not need to reset your wallpaper after updating.

Can I use a video as my Mac background?

No. Mac backgrounds must be still images. You cannot set a video file as your wallpaper, but you can use a slideshow of images that change quickly to create a similar effect.

How do I remove a background I uploaded and go back to Apple's gallery?

Open Wallpaper in System Settings and click any image from Apple's built-in collections. Your custom photo will no longer be set as the background. The photo file itself remains on your computer — changing the background does not delete it.

Why does my background look different on my lock screen than on my desktop?

Mac may crop or zoom the image differently depending on the screen size and aspect ratio of your lock screen versus your desktop. If the framing bothers you, try a different image or adjust your lock screen and desktop settings separately to use images with different compositions.