What if you could change that wallpaper so that you see something that you like when you start your Mac instead of the old-fashioned (but still good) default wallpaper? There is, and doing so does not require you to buy or install a third-party app as the entire job of changing wallpaper can be done from the built-in apps on your Mac.

Getting the Login Screen Wallpaper Ready

  1. First, get a high-quality image that you wish to set as the login screen wallpaper. If it is of low-quality, it will look blurred, and you are definitely not going to like that.

  2. Your image must be in PNG format or it will not work. If it is in another format, you need to first convert it to PNG. To convert to PNG, right-click on the image and select “Open With” followed by “Preview” to launch the image in Preview.

  3. When the image launches in Preview, click on the “File” menu and select “Save As…” to save the image in PNG format. If you do not see the Save As option, hold down the “Option” key on your keyboard and you should be able to see it.

  4. On the following screen, enter “com.apple.desktop.admin.png” (without quotes) as the image name, select “PNG” from the Format dropdown menu, and finally click on “Save.” The image should be saved in the directory where the original image exists. The reason you used that particular name for the image is because that is the name Apple uses for the login screen wallpaper on its Macs.

The image is now ready to be used.

Changing the Login Screen Wallpaper

  1. Right-click on the image that you saved above as PNG and select “Copy” to copy the image to your clipboard.

  2. Now, click on the “Go” menu in the Finder menu bar and select “Go to Folder…” Alternatively, you can use the “Command + Shift + G” keyboard shortcut to launch the “Go To Folder” feature.

  3. Enter in the following location in the “Go To Folder” panel and click on “Go.”

  4. Once there, find the image named “com.apple.desktop.admin.png,” right-click on it and select “Rename.”

Enter “com.apple.desktop.admin.backup.png” as the new name for the image and press Enter to save the new name. You are renaming the original image so that it does not get overwritten by the new image that you are going to use and that you have a backup of the original image. 5. Right-click inside that directory and select “Paste Item” to paste the image you wish to use.

  1. You can see the newly added image by clicking on your username in the top-right corner and selecting “Login Window…”.

Conclusion

If you are simply bored of seeing the same image as the wallpaper of your Mac’s login screen, the above guide wI’ll help you change that to something you really like.