Mac OS X: How to start up in single-user or verbose mode

Summary

You can use key combinations to start up the computer in either single-user mode or verbose mode. These may be used for troubleshooting or software development.

Products Affected

Mac OS X 10.0, Mac OS X 10.1, Mac OS X 10.2, Mac OS X 10.3, Mac OS X 10.4, Mac OS X 10.5, Mac OS X 10.6, Mac OS X Server

Starting up in single-user or verbose mode

    1. Shut down your Mac if it is on.
    2. Press the power button to start the computer.
    3. Immediately press and hold the Command (Apple) key and one of the following:
    • the "s" key for single-user mode.  (Command-S)
    • the "v" key for verbose mode.  (Command-V)
You have successfully entered single-user or verbose mode when you see white text appear on the screen.

To exit single-user mode type reboot  then press Return. Verbose mode exits automatically when the computer's startup process progresses sufficiently and the blue screen appears.

If the computer does not progress beyond verbose mode, and does not show progression messages, press the power button until the computer shuts down. See this article for information about troubleshooting startup issues.

Additional Information

Notes 

  • If you do not develop software, verbose and single-user modes are only needed when troubleshooting a startup issue.
  • You cannot enter single-user or verbose mode if the computer owner or administrator has enabled Open Firmware Password Protection.
  • When in single-user mode, the keyboard layout is US English.
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