How to Reset NVRAM, PRAM and SMC on a Mac

You can reset NVRAM (still often called PRAM) and the SMC only on an Intel Mac. On a Mac with Apple silicon there is nothing to reset by hand: Apple says the NVRAM reset steps don't apply and aren't needed, and that the SMC resets automatically when you plug the Mac in and restart or shut it down. So the first step for "reset PRAM Mac" is finding out which Mac you have, and the second is checking whether the symptom is one these resets can touch at all.

On an Intel Mac, the NVRAM reset is Option-Command-P-R held at startup for about 20 seconds. The SMC reset depends on the model: Macs with the Apple T2 Security Chip, older notebooks and desktops each have their own sequence, all listed below from Apple's NVRAM article and SMC article.

Which Mac do you have?

Choose Apple menu › About This Mac. Apple's Apple silicon article says a Mac with Apple silicon shows an item labeled Chip, and an Intel Mac shows Processor followed by an Intel processor name.

On an Intel Mac, the SMC steps also depend on whether it has the Apple T2 Security Chip. Apple's T2 article gives the check: hold Option, choose Apple menu › System Information, then select Controller or iBridge in the sidebar, depending on your macOS version. If you see Apple T2 chip on the right, the Mac has one.

What NVRAM and the SMC actually hold

They are two different things, which is why they fix different symptoms.

NVRAM is, in Apple's words, a small amount of memory that your Mac uses to store and quickly access certain system settings. Apple's examples are sound volume, display resolution, startup-disk selection and time zone. PRAM is the older name for the same idea on earlier Macs, and Apple's article covers both. Resetting it puts those few settings back to their defaults; it does not touch your files, apps or user preferences in the Library.

The SMC, the System Management Controller, is responsible for managing power on an Intel Mac. Apple's article ties it to the power button, power to the USB ports, fans, behavior when the lid opens and closes, sensors and status lights. Resetting it clears the controller's state, which is why Apple lists power, battery, fan and heat symptoms for it.

Neither one stores your data, caches or software, so neither reset frees storage, speeds up a slow Mac in general or repairs an app.

Reset NVRAM on an Intel Mac

1. Shut down the Mac.
2. Turn it on and immediately press and hold Option, Command, P and R together.
3. Release the keys after about 20 seconds. Apple notes the Mac might appear to restart during that time, for example you might hear a startup sound more than once or see the Apple logo more than once.
4. After the Mac finishes starting up, open System Settings and readjust anything that was reset, such as volume, display resolution, startup disk or time zone.

Hold all four keys at the same time, not one after another. Apple's startup key combinations page adds three practical notes: shut down first instead of restarting if a combination does not register, use a built-in or wired keyboard if you can, and turn off a firmware password first if one is set, because some combinations won't work with it.

Apple also recommends resetting NVRAM before you sell, trade in or recycle an Intel Mac.

Reset the SMC on an Intel Mac with the T2 chip

Notebook (MacBook Air or MacBook Pro with T2):

1. Shut down, then press and hold the power button (or Touch ID) for 10 seconds, release it, and turn the Mac on.
2. If the problem remains, shut down again. On the built-in keyboard, press and hold Control and Option on the left side and Shift on the right side for 7 seconds, then keep holding them and also press and hold the power button for another 7 seconds.
3. Release all keys and turn the Mac on.

Desktop (iMac, Mac mini or Mac Pro with T2):

1. Shut down and unplug the power cord.
2. Wait 15 seconds, then plug the power cord back in.
3. Wait 5 seconds, then turn the Mac on.

Reset the SMC on an Intel Mac without the T2 chip

Notebook: shut down, then press and hold Shift, Control and Option on the left side of the built-in keyboard together with the power button. Keep holding all four for 10 seconds, release them, and turn the Mac on.

Desktop: shut down and unplug the power cord, wait 15 seconds, plug it back in, wait 5 seconds, and turn the Mac on.

On Apple silicon: what to do instead

Apple's SMC article is direct: make sure the Mac is plugged in, then choose Apple menu › Restart or Shut Down. No other steps are needed, because the SMC resets automatically on Mac with Apple silicon. The NVRAM article says the reset steps don't apply to Apple silicon and aren't needed.

That leaves the steps that do apply. If a setting such as resolution, volume or startup disk looks wrong, change it in System Settings first, which Apple says is usually all you need. For a problem that appears at login, start in safe mode to see whether a login item or extension is involved. Holding Option-Command-P-R on an Apple silicon Mac is not a hidden version of the Intel reset.

Symptoms these resets can and cannot fix

Apple says most likely you don't need to reset the SMC. The symptoms it lists are specific:

Fast fans are the case to be most careful with. A fan that spins up because a process is using a lot of CPU is the fan doing its job, and resetting the SMC will not change that. Check the load first; if a real workload explains the heat, there is nothing to reset. Mole's Status view shows CPU load, temperatures and fan speed side by side, which makes "is this fan reacting to something?" a quick read. It does not reset the SMC or NVRAM.

What these resets cannot fix: a slow Mac in general, a full startup disk, an app that crashes, Wi-Fi drops, a problem caused by a login item, or battery wear. Battery cycle count and maximum capacity are a property of the battery, not a setting the SMC stores.

How to tell whether it worked

Retest the exact symptom you started with, under the same conditions. For a charging problem, connect the same adapter and watch the battery status. For fans, compare the fan behavior with the CPU load at the same task. For an NVRAM reset, check the setting you were chasing, and expect to readjust volume, resolution or time zone afterward, because resetting returns them to defaults.

If the symptom is unchanged after one correct reset, repeating it does not help. Move to the next step Apple suggests for that symptom, or to hardware service.

FAQ

How do I reset PRAM on a Mac?

On an Intel Mac, shut down, turn it on and immediately hold Option, Command, P and R together for about 20 seconds. PRAM and NVRAM use the same key combination. On a Mac with Apple silicon there is no manual reset and Apple says one isn't needed.

How do I reset NVRAM on an M1, M2 or later Mac?

You don't. Apple says the NVRAM reset steps don't apply to Mac computers with Apple silicon and aren't needed. Adjust the setting in System Settings instead, or restart the Mac.

How do I reset the SMC on a MacBook with Apple silicon?

Plug it in, then restart it or shut it down from the Apple menu. Apple says no other steps are needed because the SMC resets automatically on Apple silicon.

Will resetting NVRAM or SMC delete my files?

No. NVRAM holds a few settings such as volume, display resolution, startup disk and time zone, and the SMC manages power, fans and related hardware behavior. Neither reset touches your documents, apps or storage.

Does resetting the SMC fix a slow Mac or a loud fan?

Usually not. A loud fan usually means something is using the CPU, and a slow Mac usually has a software or storage cause. Apple lists fans running fast as an SMC symptom on Intel Macs, but check the CPU load before resetting.