Pogue's Basics: The master class on capturing screenshots

There are all kinds of reasons you might want to capture your screen as a graphic. Maybe you’re writing up instructions, illustrating a computer book, or collecting proof of some secret screen you found buried in a game. You can take pictures of the entire screen or capture only the contents of a rectangular selection.

In Windows, you can press the Print Screen (or PrtScn) key to copy a picture of the whole screen to the Clipboard; add the Alt key if you want to capture only the active window.

On the Mac, it’s Command-Shift-3 to capture the whole screen, or Command-Shift 4 to grab a region of the screen. (You can change these keystrokes to anything you like, in System Preferences.) If

If you hold down the Control key as you click or drag, you copy the screenshot to your Clipboard, ready for pasting, rather than saving it as a new graphics file on your desktop.

But on the Mac, that’s only the beginning of the fun you can have by holding down screenshot keys:

  • Space bar. While you hold down the space bar with one hand, your selection rectangle is frozen in size and shape. With your mouse, you can move the cursor with the selection rectangle attached, the better to fine-tune your positioning relative to your target.
  • Shift key. When you hit Shift, you confine the dragging action of your mouse to a single dimension: horizontal or vertical. Which dimension depends on how you move your mouse after you hit Shift. For example, suppose you drag out a two-inch square and then pause. With the mouse button still down, you press Shift. If you now continue to drag downward, the selected area maintains a fixed width; you’re increasing only the rectangle’s height.
  • Option key. If you hold down Option after beginning to drag, you create a rectangular selection that grows from the center point outward. That is, it treats your initial click as the rectangle’s center point, rather than as a diagonal corner.
  • Esc. If you change your mind about taking a screenshot, tap Esc. The darkened selection area disappears, and you’ve exited screenshot mode.
  • You can neatly snip one screen element out from its background—like a window or a menu. The trick is to press Command-Shift-4 as usual—but then, instead of dragging diagonally, tap the space bar. Your cursor turns into a tiny camera. Move it so the misty-blue highlighting fills the window or menu you want to capture—and then click. The resulting picture file snips the window or menu neatly from its background.

And if all of these keys are too much to remember? There’s an app for that. Windows comes with a little program called Snipping Tool, and the Mac comes with the Grab app, for capturing screenshots. Happy shotting!

Adapted from “Pogue’s Basics: Tech” (Flatiron Press), by David Pogue.