Command + Shift + 4: part of the screen

The selection capture, and the one shortcut worth learning the modifiers for — Space, Option and Shift each change what happens mid-drag.

Updated 16 September 2026

The basic capture#

Press the shortcut and the cursor becomes crosshairs with pixel coordinates beside it. Drag a rectangle, release, and the file lands on your desktop. If you want the whole screen instead, Cmd+Shift+3 does it in one press — see capturing the entire screen.

Esc cancels at any point.

The modifiers, which is where this gets good#

These all work while the crosshairs are active or mid-drag, and none of them are signposted anywhere in the interface.

Space — capture a window

Tap Space before dragging and the crosshairs become a camera icon. Hover over any window and it highlights blue; click to capture it, cropped exactly to its edges with a drop shadow.

It works on more than windows: the Dock, the menu bar, an open menu, a Notification Center banner, and individual Desktop widgets all highlight separately. It's the cleanest way to capture a single interface element.

Hold Option as you click to drop the drop shadow and get a flat, tightly cropped image. Better for documentation, where a fake shadow just adds grey margin.

Space held mid-drag — reposition the box

Start dragging, then hold Space and move the mouse. The selection keeps its exact dimensions and slides around. Release Space to resize again.

Use this when you need a capture at a specific size: get the dimensions right anywhere on screen, then slide the box over your target.

Option mid-drag — resize from the centre

Holding Option while dragging expands the selection outward from its centre instead of from the corner you started at. Useful for centring a box on something.

Shift mid-drag — lock one edge

Holding Shift freezes every edge but the last one you moved. Drag a box slightly too short and you can extend just the bottom, rather than starting over.

Coordinates are a free measuring tool#

The numbers beside the crosshairs are live pixel coordinates, and they change to width × height as you drag. That makes this shortcut a screen ruler — drag across an element to read its size, then press Esc. No capture, no app, no file. For a selection you can adjust before committing, and for screen recording, use the capture toolbar instead.

Clipboard instead of a file#

Cmd+Ctrl+Shift+4. Same selection behaviour, image goes to the clipboard only.

The selection capture is the one most Mac users settle on, and the other two numbered shortcuts sit beside it.