PRAM Reset | ⌘ + ⌥ + P + R | If your Mac is using a firmware password, it ignores this key combination or starts up from macOS Recovery |
Recovery | Command (⌘)-R | 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. If your Mac is using a firmware password, you're asked to enter the password. |
Startup Manager | Option (⌥) | allows you to choose other startup disks or volumes, if available. If your Mac is using a firmware password, you're asked to enter the password. |
Safe mode | Shift (⇧) | |
Hardware Test / Diagnostics | D | Option-D to start up from this utility over the Internet. |
NetBoot server | N | Start up from a NetBoot server, if your Mac supports network startup volumes. To use the default boot image on the server, hold down Option-N instead. |
single-user mode | Command-S | This key combination requires macOS High Sierra or earlier. |
target disk mode | T | |
verbose mode | Command-V | |
Eject removable media | Eject (⏏) or F12 or mouse button or trackpad button | |