There are two main screen saver formats for the Mac OS X operating system: the .qtz and .saver formats; the methods of installing them vary slightly. The .saver file format is the traditional screen saver format, while the .qtz screen saver format was designed using the Quarts Composer.Continue Reading
Unless the screen saver was downloaded from the App Store, screen saver formats can no longer be added just by double-clicking the file, as was the case with earlier Mac OS versions. The following shows how to install and activate new screen savers on any device running OS X Maverick or Yosemite and later.
Download the desired screen saver file from reputable third party screen saver source. Keep in mind that files from unknown or untrustworthy sources may have hidden programs that can damage or compromise the security of a computer.
Search for the downloaded file with the Finder and then right click on the screen saver with the .saver file name extension. A prompt will ask for confirmation for opening the file. Choose Open and then Install. Proceed to the screen saver list and activate the new screen saver, which was added to the list.
Using the Finder, locate the newly downloaded .qtz file. Hit Command+Shift+G and then type ~/Library/Screen Savers and then click Go. Drag and drop the .qtz file into the folder. This method also works with .saver screen saver files.