What a complete reset does and when you need one

A complete reset wipes your Mac and returns it to the state it left the factory — all your files, programs, and settings are erased. This is different from restarting, which just turns the computer off and back on. A reset is useful when you are selling or giving away your Mac, when your system has become too slow or unstable to fix another way, or when you want to remove malware that ordinary deletion cannot touch.

The process takes between one and three hours depending on your Mac's age and storage size. You will need your Apple ID password, because modern Macs require it to complete the reset. If you have forgotten your password, you will need to reset it through Apple's website before you start. You should also back up any files you want to keep — once the reset finishes, recovery is extremely difficult.

There are two main paths: erasing through System Settings (the simpler route for most people) and erasing through Recovery Mode (necessary if your Mac will not start normally or if you want to erase the drive that contains your operating system). Both methods result in the same clean state.

Key Takeaways

  • Back up all files you want to keep before starting, because a complete reset permanently deletes everything on your Mac.
  • You will need your Apple ID password to finish the reset, so have it ready or reset it through Apple's website first.
  • The simplest method is erasing through System Settings if your Mac starts normally; Recovery Mode is necessary only if your Mac will not boot.
  • The entire process takes one to three hours and leaves your Mac in the same state as when it came from the factory.
  • After the reset finishes, your Mac will restart and ask you to set up as if it were new, including choosing a language and creating a user account.

Back up your files before you start

Before you erase anything, copy all files you want to keep to an external drive or cloud storage. The reset process cannot be undone once it begins. Open Finder, plug in an external hard drive or USB drive, and drag your Documents, Desktop, Downloads, and any other folders containing files you need into the external drive window. This takes as long as your files are large — a few gigabytes might take 10 minutes, while 500 gigabytes could take an hour or more.

If you use iCloud Drive, Photos, or other cloud services, your files may already be stored in the cloud. Sign into your iCloud account on a different device or at iCloud.com to confirm your important files are there. You can also use Time Machine, Apple's built-in backup tool, to create a complete snapshot of your Mac before the reset. To set up Time Machine, open System Settings, click General, then Time Machine, and follow the prompts to choose an external drive.

Do not skip this step. Once the reset completes, the only way to recover deleted files is through expensive data recovery services, and even those do not always work.

Reset your Mac through System Settings if it starts normally

If your Mac boots up and you can log in, this is the fastest method. Click the Apple menu in the top-left corner, then System Settings. In the sidebar on the left, scroll down and click General. At the top of the General window, click Transfer or Reset. You will see two options: Transfer and Reset. Click Reset.

A window will appear asking which content you want to erase. Choose Erase All Content and Settings. Your Mac will ask you to confirm your Apple ID password — type it in and click Continue. The system will then ask whether you want to keep or remove your Apple ID from the Mac. If you are selling the Mac, choose Remove so the new owner can set up their own account. If you are keeping it, choose Keep.

Click Continue again. Your Mac will show a countdown timer and begin erasing. The screen will go black, and you will see a progress bar. Do not turn off your Mac or unplug it during this time. When the erase finishes, your Mac will restart automatically and show the setup screen, just as if it were brand new.

Use Recovery Mode if your Mac will not start normally

If your Mac will not boot into the normal login screen, or if you want to erase the drive that contains your operating system itself, you need Recovery Mode. Shut down your Mac completely. Press the power button to turn it on, then when ready hold down Command and R together until you see the Apple logo or a spinning globe. Keep holding until the Recovery window appears — this usually takes 30 seconds to two minutes.

Once Recovery Mode loads, you will see a menu with several options. Click Disk Utility. In the window that opens, you will see your Mac's hard drive listed on the left side — it is usually called Macintosh HD or Macintosh HD - Data. Click it once to select it, then click the Erase button at the top. A dialog box will ask for a name for the drive (you can leave it as Macintosh HD) and a format. Leave the format set to APFS, which is the standard for modern Macs. Click Erase.

Disk Utility will erase the drive, which takes 5 to 15 minutes depending on the drive size. When it finishes, close Disk Utility and you will return to the Recovery menu. Click Reinstall macOS and follow the prompts to read and install a fresh copy of your operating system. This step takes 30 minutes to an hour. When it finishes, your Mac will restart and show the setup screen.

Complete the setup process after the reset

After your Mac restarts following the reset, it will display the setup assistant, the same screen you would see if you had just bought a new Mac. Choose your language and country, then connect to your Wi-Fi network. You will be asked whether you want to transfer information from another Mac or restore from a Time Machine backup. If you are selling the Mac, click Do Not Transfer. If you are keeping it and want to restore your files, you can restore from the backup you created earlier.

Next, you will create a new user account. Enter a full name, a short account name (used for login), and a password. Write down the password somewhere safe — you will need it to log in and to make system changes later. You will also be asked to set up your Apple ID. If you are keeping the Mac, sign in with your own Apple ID. If you are giving the Mac away, skip this step and let the new owner set up their own account.

The setup process will also ask about Siri, location services, and analytics. You can turn these on or off based on your preference. When setup finishes, you will see the desktop. Your Mac is now completely reset and ready to use, sell, or give away.

What to do if the reset gets stuck or fails

If your Mac freezes during the erase process and does not respond for more than 10 minutes, force it to shut down by holding the power button for 10 seconds until the screen goes black. Wait 30 seconds, then press the power button again to turn it back on. If you were in System Settings when it froze, your Mac may have partially erased — try the reset again from the beginning. If you were in Recovery Mode, your Mac should restart into Recovery Mode automatically, and you can try Disk Utility again.

If you see an error message about not having enough space, your Mac may not have room to complete the erase. This is rare but can happen on very full drives. Restart your Mac normally, delete large files or programs you do not need, empty the Trash, and try again. If the error persists, use Recovery Mode and Disk Utility instead, which can erase even when space is very low.

If you forget your Apple ID password and cannot reset it through Apple's website, you will not be able to complete the reset. Contact Apple Support with proof of purchase — they can help you regain access to your account or verify that you own the Mac.

Selling or giving away your Mac after reset

Once the reset is complete and your Mac is showing the setup screen, it is safe to hand over to someone else. The new owner will create their own account and set up the Mac as if it were brand new. They will not see any of your files, programs, or settings. If you included your Apple ID during setup, remove it before handing over the Mac. Go to System Settings, click General, then Transfer or Reset, and choose Remove Apple ID.

If you are selling your Mac, include the power adapter and any original cables or documentation you have. Take a photo of the Mac's serial number (found on the bottom or in System Settings under About) for your records. If the buyer has trouble with the reset Mac, remind them that they can always perform another reset themselves using the same steps.

Frequently Asked Questions

Will I lose my photos and documents if I do a complete reset?

Yes. A complete reset erases everything on your Mac, including photos, documents, programs, and settings. You must back up any files you want to keep before starting. Use an external drive, cloud storage like iCloud, or Time Machine to save your files first.

Can I undo a reset after it starts?

No. Once the erase process begins, it cannot be stopped or reversed. This is why backing up your files beforehand is critical. If you realize you forgot to back up something important, stop the reset when ready by shutting down your Mac, and back up your files before trying again.

Do I need to reinstall macOS after erasing, or does it come back automatically?

If you use System Settings to erase, macOS reinstalls automatically when your Mac restarts. If you use Recovery Mode and Disk Utility, you must manually click Reinstall macOS in the Recovery menu after erasing. Either way, you end up with a fresh copy of macOS and the setup screen.

What if I do not remember my Apple ID password?

Go to iforgot.apple.com on another device or computer and follow the steps to reset your password. You will need access to the email address or phone number associated with your Apple ID. Once you have reset your password, use the new one to complete the Mac reset.

How long does a complete reset actually take?

The erase itself takes 5 to 30 minutes depending on your drive size. Reinstalling macOS takes 30 minutes to an hour. The setup process takes 10 to 20 minutes. Total time is usually one to three hours. Older Macs or those with large drives may take longer.