To use any of these key combinations, press and hold the keys immediately after pressing the power button to turn on your Mac, or immediately after your Mac begins to restart. Keep holding until the described behavior occurs.
If your Mac is using a firmware password, you might need to enter the firmware password before startup completes.
|Hold during startup||Description|
|Shift (⇧)||Start up in Safe Mode.|
|Option (⌥)||Start up to Startup Manager, which allows you to choose other startup disks, if available.|
|C||Start up from an available CD, DVD, or USB thumb drive that contains a valid operating system for your Mac. Or use Startup Manager, as described above.
|D||Start up from the built-in Apple Hardware Test or Apple Diagnostics utility, depending on your Mac model. Or use Option-D to start up from this utility over the Internet.|
|N||Start up from a compatible NetBoot server, if available. To use the default boot image on the NetBoot server, hold down Option-N instead.|
|Option-Command (⌘)-P-R||Reset NVRAM or PRAM.|
|Command-R||Start up from the built-in macOS Recovery system. Or use Option-Command-R or Shift-Option-Command-R to start up from macOS Recovery over the Internet. macOS Recovery installs different versions of macOS depending on the key combination you use while starting up.
|Command-S||Start up in single-user mode.|
|T||Start up in target disk mode.|
|X||Start up from your macOS startup disk when your Mac would otherwise start up from a non-macOS startup disk, such as a Windows partition. Or use Startup Manager, as described above.|
|Command-V||Start up in verbose mode.|
|Eject (⏏), F12, mouse button, or trackpad button||Eject removable media, such as an optical disc.|