What a factory reset does and when you need one

A factory reset erases everything on your Mac — all files, programs, settings, and user accounts — and reinstalls the original operating system. After the reset, your computer looks and works exactly as it did the day it left the factory. You should do this if you are selling or giving away the Mac, if it has become too slow or buggy to use, or if you want to start completely fresh without keeping any of your old data.

A factory reset is different from restarting or updating. It is permanent and cannot be undone, so back up anything you want to keep before you start. If you are not sure whether you need a full reset — for example, if your Mac is just running slowly — try restarting it first or running Disk Utility to repair the drive. Those steps often fix problems without erasing anything.

Key Takeaways

  • Back up all your files to an external drive or cloud storage before starting, because a factory reset deletes everything on your Mac.
  • Sign out of iCloud, Apple ID, and Find My Mac before you begin, or you may not be able to use the computer afterward without your password.
  • The reset process takes 30 minutes to two hours depending on your Mac model and internet speed, and your computer will restart several times.
  • After the reset finishes, your Mac will boot into the setup screen as if it were brand new, and you can choose not to restore any old data.

Back up your files before you start

Before you erase anything, copy all the files you want to keep to an external hard drive, USB flash drive, or cloud service like iCloud Drive or Google Drive. Plug in the external drive, open Finder, and drag your Documents, Desktop, Photos, and any other folders you need into the drive's window. This step takes the longest part of the whole process, so give yourself time.

If you use Time Machine (Apple's built-in backup tool), plug in an external drive, go to System Settings, click General, then Time Machine, and turn it on. Let it run until it says "Latest backup: now" — this can take several hours if you have a lot of files. Time Machine saves everything, so if you restore from it later, you will get back all your programs and settings too.

Sign out of iCloud and Find My Mac

Open System Settings (the gear icon in your dock or Applications folder). Click your name at the top of the sidebar. Scroll down and click "Sign Out." Your Mac will ask whether you want to keep a copy of your iCloud data on this computer — choose "Keep a Copy" if you want to save it, or "Don't Keep" if you do not. Then enter your Apple ID password to confirm.

Next, go back to System Settings, click General, then click "Transfer or Reset" at the bottom of the left sidebar. You should see "Erase All Content and Settings" as an option. If you do not see it, your Mac is too old to use this method — skip to the next section for the older process instead.

Use Erase All Content and Settings (Mac with Apple Silicon)

If your Mac has an Apple Silicon chip (M1, M2, M3, or newer — check by clicking the Apple menu and selecting "About This Mac"), use this method. In System Settings, go to General, then "Transfer or Reset," and click "Erase All Content and Settings." Your Mac will warn you that this cannot be undone. Click "Continue."

Your Mac will ask for your Apple ID password one more time. Enter it and click "Erase." The computer will restart and show a progress bar. Do not turn it off or unplug it. The process takes 15 to 30 minutes. When it finishes, your Mac will restart and show the setup screen, just like a brand new computer. You can now set it up as a new user or give it to someone else to set up.

Use Recovery Mode (Intel Mac or older Apple Silicon)

If your Mac is older or has an Intel processor, restart it and when ready hold down Command + R until you see the Apple logo or a spinning globe. This boots your Mac into Recovery Mode. Wait for the macOS Utilities window to appear — this can take a few minutes.

Click "Disk Utility" and then "Continue." In the left sidebar, click your main drive (usually called "Macintosh HD"). Click the "Erase" button at the top. A dialog will appear asking for a name and format. Leave the name as "Macintosh HD" and make sure the format is "APFS" (or "Mac OS Extended" if your Mac is very old). Click "Erase" and wait for it to finish — this usually takes 5 to 10 minutes.

Reinstall macOS after erasing the drive

After Disk Utility finishes erasing, close it and you will be back at the macOS Utilities window. Click "Reinstall macOS" and then "Continue." Your Mac will read the operating system from Apple's servers — this requires a working internet connection and takes 20 to 60 minutes depending on your speed. Do not close this window or turn off your computer.

When the read finishes, your Mac will restart automatically and begin installing the operating system. You will see a progress bar and the message "About X minutes remaining." Your computer may restart several times during this step. Let it finish without interrupting it. When installation is complete, your Mac will restart and show the setup screen.

Set up your Mac after the reset

Your Mac will now walk you through the setup process, asking you to choose a language, connect to Wi-Fi, and create a new user account. You can create a completely new account or sign in with an Apple ID. If you are giving the Mac to someone else, let them complete this setup instead of doing it yourself.

If you backed up your files and want to restore them, you can do that after setup is complete. Plug in your external drive, open Finder, and copy your files back to the appropriate folders. If you used Time Machine, you can restore from that backup by going to System Settings, General, Time Machine, and clicking "Restore from Time Machine Backup" during the initial setup.

Frequently Asked Questions

Can I undo a factory reset?

No. A factory reset permanently deletes all data on your Mac. The only way to recover files is if you backed them up beforehand using Time Machine, an external drive, or cloud storage. This is why backing up before you start is so important.

What if I forgot my Apple ID password?

You will need your password to sign out of iCloud before erasing. Go to iforgot.apple.com to reset your password before you start the factory reset process. If you cannot reset it, contact Apple Support — they can help you regain access to your account.

How long does a factory reset take?

The whole process usually takes 30 minutes to two hours, depending on your Mac model, how much data is on it, and your internet speed. Downloading and installing macOS takes the longest. Do not turn off your computer during this time.

Do I need an internet connection?

Yes. Your Mac needs to read macOS from Apple's servers during the reinstall step. Use a wired Ethernet connection if possible, because it is faster and more reliable than Wi-Fi. If you do not have internet access, you can create a bootable USB drive on another Mac, but that is more complicated.

What if my Mac gets stuck during the reset?

If the progress bar does not move for more than an hour, try restarting by holding the power button for 10 seconds. Then boot back into Recovery Mode (Command + R) and try the erase and reinstall steps again. If it keeps failing, your drive may be damaged — contact Apple Support or visit an Apple Store.