Reposition marquee while selecting^‡

Any marquee tool (except single column and single row) + spacebar-drag

Any marquee tool (except single column and single row) + spacebar-drag

Add to a selection

Any selection tool + Shift-drag

Any selection tool + Shift-drag

Subtract from a selection

Any selection tool + Alt-drag

Any selection tool + Option-drag

Intersect a selection

Any selection tool (except Quick Selection tool) + Shift-Alt-drag

Any selection tool (except Quick Selection tool) + Shift-Option-drag

Constrain marquee to square or circle (if no other selections are active)^‡

Shift-drag

Shift-drag

Draw marquee from center (if no other selections are active)^‡

Alt-drag

Option-drag

Constrain shape and draw marquee from center^‡

Shift + Alt-drag

Shift + Option-drag

Switch to Move tool

Control (except when Hand, Slice, Path, Shape, or any Pen tool is selected)

Command (except when Hand, Slice, Path, Shape, or any Pen tool is selected)

Switch from Magnetic Lasso tool to Lasso tool

Alt-drag

Option-drag

Switch from Magnetic Lasso tool to polygonal Lasso tool

Alt-click

Option-click

Apply/cancel an operation of the Magnetic Lasso

Enter/Esc or Control + . (period)

Return/Esc or Command + . (period)

Move copy of selection

Move tool + Alt-drag selection^‡

Move tool + Option-drag selection‡

Move selection area 1 pixel

Any selection + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†

Any selection + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†

Move selection 1 pixel

Move tool + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†‡

Move tool + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†‡

Move layer 1 pixel when nothing selected on layer

Control + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†

Command + Right Arrow, Left Arrow, Up Arrow, or Down Arrow^†

Increase/decrease detection width

Magnetic Lasso tool + [ or ]

Magnetic Lasso tool + [ or ]

Accept cropping or exit cropping

Crop tool + Enter or Esc

Crop tool + Return or Esc

Toggle crop shield off and on

/ (forward slash)

/ (forward slash)

Make protractor

Ruler tool + Alt-drag end point

Ruler tool + Option-drag end point

Snap guide to ruler ticks (except when View > Snap is unchecked)

Shift-drag guide

Shift-drag guide

Convert between horizontal and vertical guide

Alt-drag guide

Option-drag guide

^†Hold down Shift to move 10 pixels

^‡Applies to shape tools