Mac OS X Shortcuts

Shortcuts Common to Most Applications

hold option key with menu open	show additional menu options
spacebar	simulate a mouse click on focused object (i.e., the button or control that has a blue halo around it)
command-shift-?	Search application help. As of 10.5, this also FAYT searches available menu items. It also activates the menu bar as keyboard navigable if the search string is empty.
command-shift-+	increase font size
command--	decrease font size
command-,	preferences
command-?	help
command-shift-:	show spelling window
command-;	check spelling
command-A	select all
command-C	copy
command-D	duplicate
command-shift-C	show colors
command-E	use selection for find
command-F	find
command-G	find next
command-shift-G	find previous
command-H	hide application windows
command-option-H	hide windows of other applications
command-J	scroll to selection
command-M	minimize (equivalent to double-clicking the title bar)
command-option-M	minimize all application windows (equivalent to option-double-clicking the title bar or option-clicking the minimize button)
command-N	new
command-O	open
command-P	print
command-Q	quit
command-S	save
command-S	save
command-shift-S	save as
command-option-S	save all
command-T	show fonts
command-V	paste
command-W	close window
command-option-W	close all application windows (equivalent to option-clicking the close button)
command-shift-W	close a file and its associated windows
command-X	cut
command-Z	undo
command-shift-Z	redo

Shortcuts on laptops

On most Mac laptops, some of the function keys (F1 - F12) are used to control hardware features:

F1	decrease brightness
F2	increase brightness
F3	mute on G4s, decrease volume on G3s
F4	decrease volume on G4s, increase volume on G3s
F5	increase volume on G4s, numlock on G3s
F6	Num lock on G4s, mute on G3s
F7	Display mode (mirror or extend external display)
F8	disable backlit keyboards (Aluminum PowerBooks)
F9	decrease keyboard brightness for backlit keyboards
F10	increase keyboard brightness for backlit keyboards
F12	eject (some Macs, namely all MacBooks, MacBook Pros, and newer PowerBooks, place a dedicated eject key next to the F12 key)

Newer Mac laptops (MacBook Pros made after February 2008, MacBooks after November(?) 2007, MacBook Airs), and the Aluminum keyboard, have a different layout for fn keys. Some keys have been added, while the numlock key has been removed and the display mode key has been integrated into the brightness key (see combinations in parenthesis)

F1	decrease brightness (command+F1 changes display mode, option+F1 brings up display prefs)
F2	increase brightness (option+F2 brings up display prefs)
F3	exposé (F3 shows all windows, control+F3 shows app windows, option+F3 brings up exposé prefs, command+F3 shows desktop)
F4	dashboard (option+F4 brings up exposé prefs)
F5	decrease keyboard brightness for backlit keyboards (option+F5 brings up keyboard prefs)
F6	increase keyboard brightness for backlit keyboards (option+F6 brings up keyboard prefs)
F7	media navigation backwards (like hitting back on Apple Remote)
F8	media play/pause (like hitting play/pause on Apple Remote)
F9	media navigation forwards (like hitting next on Apple Remote)
F10	mute volume (option+F10 brings up sound prefs)
F11	decrease volume (option+shift+F11 for incremental decrease, option+F11 brings up sound prefs)
F12	increase volume (option+shift+F12 for incremental increase, option+F12 brings up sound prefs)

Shortcuts With Global Scope

More shortcuts with global scope can be found on the Universal Access page.

command-option-esc	force quit
hold command-shift-option-escape for 4 sec	Force quit front-most application (without confirmation)
control-eject	show shutdown dialog
command-option-eject	sleep now
command-shift-Q	log out
command-shift-option-Q	log out without confirmation
command-control-eject	restart
control-shift-eject	sleep displays
command-option-control-eject	shut down
command-tab	cycle between open applications
command-`	*after* having pressed command-tab, it will cycle between open applications in reverse
command-shift-tab	cycle between open applications in reverse direction
command-`	cycle between open windows in the selected application
command-shift-`	cycle between open windows in the selected application in reverse direction
control-F4	cycle between open windows in all applications
control-shift-F4	cycle between open windows in all applications in reverse direction
F8	Spaces (Leopard only)
F9	Exposé for all windows (Panther and newer)
F10	Exposé for all windows in selected application
F11	Exposé to reveal desktop
F12	Dashboard (Tiger and newer)
control-#	Jump to a space (10.5+)
control-arrow	Cycle through spaces (10.5+)
command-space	activate Spotlight (Tiger) or switch between keyboard layouts (pre-Tiger systems)
command-option-space	open a Spotlight search in a finder "Find" window
shift-volume	Change volume without sound effect
option-shift-volume	Fine-grained volume control (10.5+ ?)
option-volume	Sound Preference Pane
option-brightness	Display Preference Pane
command-decrease-brightness	Change display mode (only on revised fn keyboard layout on Alu. keyboards, newer MBP/MBs?)
opt-"Empty Trash"	Empty trash, including locked items, without any alerts
command-escape	open front row (Press any F key (except F2) or Escape to exit)
hold shift while performing action	slow down any animation (exposé, time machine, minimize, etc)
option-drag scrollbar	smooth scrolling
option-eject	Eject secondary optical media drive (if one exists)
option-click dock icon or window	Switch to application and hide previous application
command-option-click dock icon or window	Switch to application and hide all others
command-drag menulet	re-order icon
command-drag menulet off the menu bar	remove icon from menu bar

[edit]

Command-Tab Box

Press command-tab and hold the command key to keep the box open. Release the command key to switch to the selected application.

escape	exit command-tab box (equivalent to pressing the period key (.))
H	hide application
Q	quit application
left/right arrow keys or home/end or `(grave accent)/tab	select an application (you can also aim with the mouse)
up/down arrow keys	view windows of selected application (use arrow keys to navigate, then press enter to select window)

ref: 1 2