How to reset the NVRAM on your Mac

Is your Mac running slowly or erratically? One thing you can try is resetting the NVRAM (or “non-volatile random access memory.” It’s a tiny bit of your Mac’s memory that stores certain settings in a location that macOS can access quickly. 

The settings that are stored in NVRAM depend on the type of Mac you're using and the types of devices connected to it. Info stored in NVRAM can include speaker volume, screen resolution, and startup disk selection.

If you’re experiencing issues related to these features or have had a “kernel panic,” resetting the NVRAM can help. For example, if your Mac starts up from a startup disk other than the one you've specified in Startup Disk preferences, or if a question mark icon appears briefly when your Mac starts up, you might need to reset the NVRAM. Here’s how:

  • Shut down your Mac.
  • Find Command (⌘), Option, P, and R on your keyboard.
  • Turn on your Mac.
  • Press and hold the Command-Option-P-R keys immediately after you hear the startup sound.
  • Hold these keys until the computer restarts and you hear the startup sound for a second time.
  • Release the keys.

If you have one of the new MacBook Pros (late 2016), you’ll need to take these steps instead:

  • Shut down your Mac.
  • Find Command (⌘), Option, P, and R on your keyboard.
  • Turn on your Mac.
  • Press and hold the Command-Option-P-R keys immediately after you turn on your Mac.
  • Hold these keys down for at least 20 seconds to ensure that your Mac completes the process correctly.
  • Release the keys.

After resetting NVRAM, you might need to reconfigure settings for speaker volume, screen resolution, startup disk selection, and time zone information.