Quick Look in macOS is handy for previewing files, but here’s why you may want to clear its cache from time to time.
We’ve covered previously how to use Quick Look in macOS. Using this technology, you can gain fast previews of the contents of files without having to open them by selecting them and pressing the spacebar.Each time you do that, Apple generates a small image to represent the current items displayed in the Quick Look window. Those images gets cached and over time can build up to an appreciable size.