The last section of this article offers some tips for taking more control of your screenshot selections, so be sure to check those out too.

You can also change the default file format that the screenshots are saved in by following these steps. If you'd like to change that default save location to somewhere different, simply follow the steps below. Otherwise, screenshots taken using key shortcuts are saved straight to your desktop. If you tack the Control key onto either of these shortcuts, macOS copies the captured image to the clipboard, which is useful if you want to paste it into an application that can edit or view images. Taking a screenshot is as easy as hitting Shift-Command-3 to capture the whole screen, or Shift-Command-4 to capture a portion of the screen using the mouse cursor as a crosshair selection tool (a tap of the spacebar also turns it into a camera for capturing windows). But the simplest and most common method is to use your Mac's built-in shortcut key combinations. There's also a little screen capture app in the macOS Utilities folder called Grab. Preview offers the option from its File menu. There are several ways you can take screenshots on a Mac.

How to take screenshot on mac as jpeg