Preview Files without Opening Them
Finder gives you a small preview of all your documents, so you know which is which. But sometimes, it’s too small to recognize anything. Before, you probably needed to open the file to understand what it was, but that takes too much time and RAM. Instead, you can easily preview any file or picture without opening it.
All you need to do is select the file you want to preview and press and hold the space bar until a small preview window pops up. You can see your file and even copy the text without opening an app!
What’s more impressive is that you can even add a signature to any PDF document or lightly edit a picture without opening anything.