What "wiping" a Mac means and when you need to do it

Wiping a Mac means erasing everything on the hard drive or solid-state drive and reinstalling the operating system from scratch. The computer returns to the state it was in when it left the factory—no files, no apps, no settings. You are left with a blank machine running a fresh copy of macOS.

You might wipe a Mac before selling it, giving it away, or handing it to someone else. You might also wipe it if the system has become slow, unstable, or infected with malware, and you want a clean start. Wiping is also the step you take before recycling a Mac responsibly, because it removes your personal data from the drive.

The process is different depending on whether your Mac has an Intel processor or an Apple Silicon chip (M1, M2, M3, or later). Both are straightforward, but the steps differ slightly.

Key Takeaways

  • Back up all your files before you start, because wiping erases everything on the drive permanently.
  • Intel Macs use Disk Utility to erase the drive and then reinstall macOS from Recovery Mode; Apple Silicon Macs use Erase All Content and Settings from System Settings.
  • You will need your Apple ID and password to complete the process on an Apple Silicon Mac.
  • After wiping, the Mac boots into the setup screen where you can configure it as new or restore from a backup.

Back up your files before you wipe

Before you erase anything, copy all the files you want to keep to an external drive, cloud storage, or another computer. Once the drive is wiped, those files are gone and cannot be recovered by normal means.

The easiest way is to use Time Machine, which is built into macOS. Plug in an external drive, open System Settings (or System Preferences on older Macs), find Time Machine, and click "Set Up Time Machine." Select your external drive and let it back up. This creates a complete snapshot of your Mac that you can restore later if you change your mind.

If you do not have an external drive, you can also back up to iCloud by signing into your Apple ID in System Settings and turning on iCloud Drive. This uploads your documents and desktop to Apple's servers, though it does not back up applications or system settings the way Time Machine does.

Wiping an Intel Mac using Disk Utility and Recovery Mode

Shut down your Intel Mac completely. Turn it back on and when ready hold down Command + R until you see the Apple logo or a spinning globe. This boots the Mac into Recovery Mode, where you can repair or erase the drive.

When the Recovery window appears, click Disk Utility and then Continue. In the left sidebar, select your main drive (usually called "Macintosh HD" or similar). Click the Erase button at the top.

A dialog box will ask you to name the drive and choose a format. Leave the name as "Macintosh HD" or use a name you prefer. For the format, select APFS if your Mac is running macOS 10.13 or later; if it is older, select Mac OS Extended (Journaled). Click Erase and wait for the process to finish. This usually takes a few minutes.

Once the drive is erased, close Disk Utility. You will return to the Recovery window. Click Reinstall macOS and follow the on-screen steps. The Mac will read and install the operating system, which can take 30 minutes to an hour depending on your internet speed. When it finishes, the Mac will restart and show the setup screen.

Wiping an Apple Silicon Mac using Erase All Content and Settings

Apple Silicon Macs (M1, M2, M3, and later) have a simpler built-in option. Open System Settings and click General in the sidebar. Scroll down and click Transfer or Reset. Then click Erase All Content and Settings.

The Mac will ask you to sign in with your Apple ID and password. This is a security step to prevent someone else from erasing your Mac without permission. Enter your credentials and click Continue.

You will see a warning that everything will be erased. Click Continue again. The Mac will restart and begin the erase process, which usually takes 5 to 15 minutes. When it finishes, the Mac will show the setup screen as if it just came from the factory.

What happens after the wipe is complete

Once the drive is erased and macOS is reinstalled, your Mac boots into the setup assistant. You will see screens asking you to select your language, connect to Wi-Fi, and sign in with your Apple ID. You can set up the Mac as a new computer, or you can restore from a Time Machine backup if you want to get your files and settings back.

If you are selling or giving away the Mac, do not sign in with your Apple ID. Instead, skip those steps and leave the Mac at the setup screen for the new owner. If you are keeping the Mac, sign in and choose whether to set it up as new or restore from your backup.

After setup is complete, you will need to reinstall your applications. The Mac no longer has Microsoft Office, Adobe Creative Suite, or any third-party apps you had before. You can read them again from the App Store or from the publishers' websites using your original licenses.

Troubleshooting common problems during a wipe

If your Mac gets stuck in Recovery Mode and will not boot normally, try restarting it by holding the power button for 10 seconds, then turning it back on. If it still will not start, you may need to create a bootable macOS installer on an external drive using another Mac or a Windows computer. Apple's support website has instructions for this if you need them.

If you forget your Apple ID password before wiping an Apple Silicon Mac, you can reset it at iforgot.apple.com. You will need access to the email address or phone number associated with your account. If you cannot reset it, contact Apple Support before attempting to erase the Mac.

If Disk Utility shows an error when you try to erase an Intel Mac, the drive may have a problem. Try restarting into Recovery Mode again and running Disk Utility's First Aid tool on the drive before attempting to erase. If that does not work, the drive may need professional repair.

When to call a professional instead

If your Mac will not start up at all, or if it gets stuck during the wipe process, you may need help from an Apple Store or a certified Mac technician. They can diagnose hardware problems and perform the wipe if the drive is damaged or if the Mac cannot reach Recovery Mode on its own.

If you are not comfortable with the process, or if you are wiping a Mac before selling it and want to make sure your data is completely removed, a technician can also verify that the erase was successful and that no personal information remains on the drive.

Frequently Asked Questions

Can I undo a wipe if I change my mind?

Not after the drive is erased, unless you have a Time Machine backup. If you do, you can restore from the backup during setup. If you do not have a backup, the data is gone. This is why backing up before you wipe is so important.

Do I need the original macOS disc or installation media?

No. Recovery Mode downloads and installs macOS over the internet. As long as your Mac can connect to Wi-Fi, it can reinstall the operating system on its own. You only need installation media if your Mac cannot reach Recovery Mode.

How long does it take to wipe a Mac?

The erase itself usually takes a few minutes. Reinstalling macOS can take 30 minutes to an hour, depending on your internet speed and which version of macOS you are installing. The whole process from start to finish is typically one to two hours.

Will wiping a Mac remove viruses or malware?

Yes. Because wiping erases everything on the drive and reinstalls a fresh copy of the operating system, any malware is removed. This is one reason people wipe a Mac when it has been infected.

What if I wipe the wrong drive by accident?

If you have an external drive connected during the wipe, make sure you select only your internal Mac drive in Disk Utility. Double-check the drive name and size before clicking Erase. If you accidentally erase an external drive, the data may be recoverable by a data recovery service, but it is not may provide.