15 Startup Key Combinations for Mac

Your Mac and OS X have a variety of startup keys and key combinations you can use to affect how the device starts up. Shift key, for instance, starts your Mac in Safe mode, and C (or c) starts up from a bootable CD, DVD, or thumb drive. Command-S is for "single-user mode," which essentially means booting to the command line.

Apple Command Key

The Apple Key, or the Command Key

I was personally familiar with these and several others, but it turns out there are 15 total combinations, thanks to a KnowledgeBase article Apple posted. I'm betting many of you don't know them all, either, so here they are.

The links below point to other support documents on Apple's website.

15 Startup Key Combinations for Mac
Hold during startupDescription
Shift ⇧Start up in Safe Mode.
Option ⌥Start up to Startup Manager.
CStart up from a bootable CD, DVD, or USB thumb drive (such as OS X install media).
DStart up to either Apple Hardware Test or Apple Diagnostics, depending on which Mac you're using.
Option-DStart up to either Apple Hardware Test or Apple Diagnostics over the Internet.
NStart up from a compatible NetBoot server.
Option-NStart up from a NetBoot server using the default boot image.
Command (⌘)-RStart up from OS X Recovery
Command-Option-RStart up from OS X Recovery over the Internet.
Command-Option-P-RReset NVRAM. Release the keys after you hear the startup sound again.
Command-SStart up in single-user mode.
TStart up in target disk mode.
XStart up from an OS X startup volume when the Mac would otherwise start up from a non-OS X startup volume.
Command-VStart up in verbose mode.
Eject (⏏), F12, mouse button, or trackpad buttonEject removable media, such as an optical disc.

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