Learn how to rotate wallpapers on your Mac from a folder of images for fresh auto-changing desktop backgrounds without downloading any apps for that.

You can stare at the same wallpaper all day long or spice things up a little bit by setting your Mac to cycle through a bunch of backgrounds for an ever-changing desktop experience. Just fill a folder with some images and set it as a wallpaper source in the built-in System Settings app to have macOS cycle through them periodically.
Rotate wallpapers in a folder on your Mac
Click the Finder icon in the Dock to open a new Finder window, then click File > New Folder in the menu or press the Shift + Command + N keys to create a new folder, then drop some image files onto it. Next, click the Apple menu and choose System Settings, then select Wallpaper in the sidebar. Click the Add Folder or Album button on the right side and choose the Choose Folder option, then select your wallpaper folder and hit Choose.
Scroll to the bottom of the Wallpapers section of System Settings to find your newly-added folder, then click a thumbnail to set that wallpaper as your new desktop background or hit the icon resembling two curved arrows to automatically rotate all wallpapers from that folder. To adjust the switching interval, click the menu next to Every 30 Minutes. To tell macOS to cycle through wallpapers randomly instead of sequentially, tick the box labeled Randomly.
Add or remove wallpapers from a folder
The Wallpaper section of System Settings automatically recognizes changes in any linked wallpaper folders. For example, if you add to or remove images from your folder, the changes will be automatically reflected in System Settings.
Remove your wallpaper folder from System Settings
If you no longer want to use a specific folder as a wallpaper source, hover over its title in System Settings and click the tiny x icon. Don’t see the icon? Force quit System Settings and retry.
On a related note: