How to properly erase your Mac before selling, recycling (or after buying used!)

Updated January 5, 2025: Added information about macOS Ventura's easier erase option.

All too often I've seen people buy a used Mac only to find that the seller did not properly erase the Mac first. Sellers sometimes just delete their documents, leaving poorly configured and obsolete apps lying around. Or worse yet a malicious security threat or connections to their old account. Here is how to properly erase a Macintosh, ensuring that:

• If you are selling or recycling your Mac, none of your personal information remains
• If you are buying a used Mac, none of the previous owner's configuration will mess things up

Take note of what system version you are running, as some of these instructions will vary depending on the version. You can find that in the Apple menu > About This Mac. Also, take note of the release year because between 2017 and 2020, Apple made some huge changes that make erasing newer models easier.

Back up any data

These steps will completely and irrecoverably erase everything on your Mac. If you have anything on this Mac that you want to keep you'll want to back it up. Photos, contacts, documents, application installers, etc. Many of these things are saved to iCloud but not necessarily. When we are done the only thing left will be a squeaky clean computer as good as from the factory.

Easy erase on newer Mac models

iMacs from 2020 or later or any other model Mac from 2018 or later are exceptionally easy to erase. This does require your computer to be running macOS 13 Ventura or later, so you should update your software first in the Apple menu > System Preferences > Software Update.

Not sure if your computer meets the requirements above? Try the instructions below. Your computer will tell you if you can't erase the computer this way.

To erase, go to the Apple menu > System Settings > General > Transfer or Reset > Erase All Content & Settings. Follow the prompts, providing your computer password and Apple Account password when prompted. You may see error messages about problems connecting to iCloud, but just ignore this; that's because you removed your computer from your iCloud account, but the apps on your computer haven't gotten the memo yet. This usually takes about 5 to 10 minutes, and your computer will restart. Once it's done, you might be asked to activate your Mac, depending on your specific model. Connect to WiFi if needed and allow the activation to run. When you get to the screen where you see "Hello" in different languages, you're all done! You can now set it up, or if you want to give it to someone else, you can press Command-Q to turn the computer off.

More difficult erase on older Mac models

If you have an iMac from 2019 or earlier or any other model Mac from 2017 or earlier, you'll have to work a little harder to erase your computer.

Update your software (optional)

If the computer is going to be reused or sold, you probably want to upgrade the software to the latest supported OS if it isn't already. If you plan to recycle the computer it doesn't matter so you can skip this.

To upgrade go to the Apple menu > System Settings > General > Software Update, or if you are running software older than macOS Ventura you'll find it in the Apple menu > System Preferences > Software Update.

Log out of your accounts

This isn't strictly necessary but it will remove one of your five allowed iTunes authorizations and will remove the computer from your iCloud account. In particular, you'll want to:

• Deactivate any third party software that has a limited number of authorizations. Most consumer-grade software doesn't do this, but some expensive professional software does. Instructions for this will vary depending on the specific software.
• Log out of iCloud. If prompted you can delete the local data, since you have all of this in iCloud already.
  • In macOS 13 Ventura or later: Apple menu > System Settings > [Your Name] > (scroll to the bottom) Sign Out
  • In macOS 12 Monterey or earlier: Apple menu > System Preferences > iCloud > Sign Out

Start up in macOS Recovery Mode

Be sure to remove all devices from your computer except for necessary items like the mouse and keyboard. You don't want to erase an external hard drive accidentally.

For macOS 10.7 or higher with an Intel processor

1. Turn your Mac off
2. Press the power button to turn the Mac back on and immediately press and hold the Command + R keys on your keyboard
3. When you see the Apple logo or globe you can release the keys
4. Follow any prompts such as entering your WiFi password, choosing your language, or entering the password for an existing user account

Bonus: If you are running macOS 10.13 High Sierra or later and you want to install the latest OS your computer supports rather than the currently installed OS, use Command + Option + R instead. You can release the keys when you see the globe, then choose your WiFi network when prompted.

Erase your disk

1. Once in Recovery Mode, click the Disk Utility from the menu and then click "Continue"
2. On the left column of Disk Utility, click your internal hard drive, usually called Macintosh HD unless you renamed it. If you only see one drive listed in the Internal Hard Drive heading, that's probably the one. Double-check that you don' thave any external hard drives connected so you can be sure you don't erase something important.
3. Click the Erase button.
4. If you have a mechanical hard drive, you'll see Security Options which you should consider using. One notch from the left is probably good enough for most people. Each pass can take a couple of hours. SSDs don't require this extra step, so most modern Macs won't give you this option.
5. You can leave the Name as it is, or you can change it to Macintosh HD. This is really just cosmetic and doesn't matter much.
6. Leave the Format set to whatever it is.
7. Click Erase Volume Group. If you don't see Erase Volume Group button, just plain Erase will do.
8. Click OK after it has finished.
9. Close Disk Utility with the red dot button.
10. Press Command-Q to shut down if you are just disposing of the computer, otherwise continue on to install the OS.

Install the OS (Optional)

If this computer is going to be reused rather than just recycled, you should install the OS so that it can start up as though it was fresh from the factory.

1. Make sure you are connected to your WiFi network by clicking the WiFi icon in the upper right corner of your screen.
2. While still in Recovery mode, click the button to reinstall the OS and follow the prompts.
3. After the OS is installed you will be greeted with the Welcome Screen. In recent versions of macOS it's Hello cycling in many languages. If you are setting this computer up for yourself you can click the continue button and walk through these steps. If you are giving the computer to someone else, press Command-Q to quit and shut down. The next time the Mac is turned on the new user will be greeted with the same welcome screen.

Requirements for OS installation

• Fast internet connection: this will download the OS from the internet. The download is about 6 to 12 GB so it could take 30 to 60 minutes, or longer if your internet speed is slow.
• For macOS 10.11 or earlier, the currently installed OS must already be in your Mac App Store account. Check this in the Apple menu > App Store > Purchased. If the currently installed OS is not on your purchase list you must upgrade to at least macOS 10.12 and then do the full erase, or solicit the account of someone who does have the currently installed version in their account.
• Compatible network connection: Most home and small business routers since about 2005 should have the appropriate configuration by default. If you are unsure click the WiFi icon in the top right corner of your screen while holding the "Option" key. In light grey lettering you will see your current security type. Or just try it and see if it works.

You must be on either:

• wired ethernet connection,
• WiFi connection without a password, or
• WiFi connection with WPA-Personal or WPA2-Personal encryption.

You cannot install via:

• captive WiFi connection (one where you get a popup on connecting such as at a coffee shop or library),
• WiFi with WEP encryption
• WiFi with WPA-Enterprise encryption
• WiFi with certificate-based encryption, or
• a connection that requires a proxy to be configured.

Photo by Kim Gorga on Unsplash