What a factory reset does and when you need one

A factory reset erases everything on your Mac and reinstalls the operating system from scratch. This means all your files, apps, settings, and accounts disappear. The Mac then boots up as if it just came from the factory—blank, with no user data.

You would do this if your Mac is running slowly due to software corruption, you're selling or giving away the computer, you want to start fresh after malware, or you're troubleshooting a problem that won't go away. It's also called an erase and reinstall or a clean install.

This is not the same as restarting your Mac or signing out of your account. A factory reset is permanent and complete. Before you start, back up anything you want to keep—photos, documents, email, everything.

Key Takeaways

  • Back up all your files before starting, because a factory reset deletes everything on the drive.
  • You need your Apple ID and password to complete the reset and sign back in afterward.
  • The process takes 30 minutes to two hours depending on your Mac model and internet speed.
  • On newer Macs with Apple Silicon chips, you use the Erase All Content and Settings tool; on older Intel Macs, you use Recovery Mode and Disk Utility.
  • After the reset finishes, your Mac boots to the setup screen and you can restore files from your backup.

Back up your files before you start

The safest way to back up is to use Time Machine, which is built into macOS. Plug in an external hard drive, open System Settings, go to General > Time Machine, click Add Backup Disk, select your external drive, and let it run. Time Machine creates hourly backups automatically after that. A full backup usually takes a few hours the first time.

If you don't have an external drive, you can back up to iCloud instead. Go to System Settings > [Your Name] > iCloud and turn on iCloud Drive. This syncs your Documents and Desktop folders to iCloud automatically. You can also manually copy important files to a USB drive or cloud service like Google Drive or Dropbox.

Write down your Apple ID and password before you proceed—you'll need them to sign back in after the reset. If you use FileVault encryption (which encrypts your drive), also write down your recovery key, which you can find in System Settings > [Your Name] > Password and Security.

Factory reset on a Mac with Apple Silicon (M1, M2, M3, or newer)

If your Mac has an Apple Silicon chip—which includes all Macs released in late 2020 or later—use the built-in Erase All Content and Settings tool. This is the simplest method.

Go to System Settings > General > Transfer or Reset. Click Erase All Content and Settings. Your Mac will ask you to confirm and will warn you that this cannot be undone. Click Continue. Enter your Apple ID password when prompted. Your Mac will restart and begin erasing. This takes 10 to 30 minutes. When it finishes, you'll see the setup screen, and you can set up your Mac as new or restore from a Time Machine backup.

Factory reset on an Intel Mac (older models)

If your Mac has an Intel processor—which includes most Macs made before late 2020—you'll use Recovery Mode and Disk Utility instead.

Shut down your Mac completely. Turn it back on and when ready hold Command + R until you see the Apple logo or a spinning globe. This boots into Recovery Mode. Wait for the macOS Utilities window to appear. Click Disk Utility and then click Continue.

In Disk Utility, select your main drive (usually called "Macintosh HD" or your Mac's name) from the left sidebar. Click the Erase button at the top. A dialog will appear asking for a name and format. Leave the name as is or type a new one. Make sure the format is set to APFS (or Mac OS Extended if your Mac is very old). Click Erase. This wipes the drive and takes a few minutes.

When erasing finishes, close Disk Utility. You'll return to the macOS Utilities window. Click Reinstall macOS and follow the prompts. Your Mac will read and install the operating system. This can take 30 minutes to an hour depending on your internet speed. Your Mac will restart several times during installation. When it finishes, you'll see the setup screen.

Set up your Mac after the reset

After the reset completes, your Mac boots to the setup screen. You'll be asked to select your language, connect to Wi-Fi, and sign in with your Apple ID. Use the Apple ID and password you wrote down earlier.

Next, you'll be asked whether to restore from a backup or set up as new. If you have a Time Machine backup, select "Restore from a Time Machine backup" and choose your backup drive. This restores all your files, apps, and settings. If you backed up to iCloud, you can sign in and let iCloud restore your Documents and Desktop folders. If you backed up files manually to a USB drive or cloud service, you can copy them back after setup finishes.

If you choose to set up as new, you'll create a new user account. You can then manually restore files from your backup afterward. This takes longer but gives you a completely clean start.

What to do if something goes wrong

If your Mac gets stuck during the reset, force it to shut down by holding the power button for 10 seconds. Then try again from the beginning.

If you forget your Apple ID password, visit iforgot.apple.com to reset it before you start the factory reset. You won't be able to complete the setup without it.

If your Mac won't boot into Recovery Mode, restart it and try holding Command + R again, or try Command + Option + R for internet recovery (which downloads the OS from Apple's servers instead of your drive). If neither works, your Mac may have a hardware problem and you should contact Apple Support or visit an Apple Store.

If the reset takes much longer than expected, check your internet connection. A slow connection can make the OS read and installation take several hours. Leave your Mac plugged in and don't interrupt the process.

Frequently Asked Questions

Will a factory reset remove viruses or malware?

Yes. A factory reset erases the entire drive and reinstalls the operating system, so any malware is removed. However, if you restore files from an infected backup, you may restore the malware too. If you suspect malware, set up as new rather than restoring from backup, then manually copy only the files you trust.

Can I undo a factory reset?

No. Once the reset finishes, the data is gone. This is why backing up beforehand is essential. If you accidentally reset without backing up, data recovery services may be able to recover some files, but it's expensive and not may provide to work.

Do I need to reinstall my apps after a factory reset?

If you restore from a Time Machine backup, your apps are restored too. If you set up as new, you'll need to reinstall apps from the App Store or by downloading installers from their websites. Your paid apps will still be tied to your Apple ID, so you won't have to pay again.

How long does a factory reset take?

The erase part takes 10 to 30 minutes on Apple Silicon Macs. On Intel Macs, erasing takes a few minutes but reinstalling the OS takes 30 minutes to an hour depending on internet speed. Restoring from a backup afterward can take another 30 minutes to several hours depending on how much data you have.

What if I need to factory reset but don't have a backup?

You can still do the reset, but you'll lose all your files. If you have time, create a backup now before proceeding. If you've already reset without backing up, contact a data recovery service, though recovery is not may provide and can be costly.