How to Change the Log in Screen Wallpaper in OS X El Capitan

Have you ever thought of customizing the login screen window on a Mac? If you are the only user of this machine setting up unique log in wallpaper is not a difficult thing.

The image you would like to use as a background photo should be a PNG file. It should also have at least the resolution of your screen, otherwise the picture will be pixelated.

1. Open the picture you would like to use as the log in wallpaper with Preview application. Do ctrl + click on the image file and choose “open with”. Select preview app from the list. You may also use file menu at the top and click “open with”

2. Click on the “File” menu at the top and choose “Save as” option. Choose PNG format and name the file as “com.apple.desktop.admin.png”. Save it on your desktop.

3. Navigate to Caches folder in the local Library. To do this use command + shift + G key combination.

Paste this path to the address bar: /Library/Caches

4. Copy and paste the image named com.apple.desktop.admin.png to Caches folder. Use command + c key combination to copy the file and command+ v in order to paste it.

5. Caches folder already contains the file with the same name so you’ll be prompted to replace, keep both files or stop. Select the “replace” option.

6. Log out from your machine and enjoy new login wallpaper.