Guide to How to Wipe a Mac or Macbook Clean

Your faithful Mac has served you well for years, but it’s time to upgrade. Whether you’re selling it, giving it to a friend, donating it, or recycling it, you first need to make sure all of your personal data is wiped clean. 

In this guide, we’ll take you through the process step-by-step, from backing up your files to encrypting your data, so you can make sure your private information stays private.

Before you do anything else, back up

Once you wipe your Mac, you won’t be able to access the data from your drive. Before you get started, you’ll want to make sure any important data on your hard drive has been backed up. Apple has a built-in backup utility called Time Machine backup software. 

While Time Machine is a good start, it doesn’t fulfill all of the requirements of a 3-2-1 backup strategy: When you set up Time Machine backups, you choose a backup disk (an external drive or network attached storage (NAS) device) that you can save your backups to. Under the 3-2-1 backup rule (three backups, on two media types, with one off-site), that means you’d still need an off-site copy of your data, preferably saved in the cloud. Ideally, you’d pair Time Machine with a product like Backblaze Computer Backup for maximum flexibility. Note that even though backups run nearly continuously with Backblaze Computer Backup, we recommend hitting the manual backup button before you wipe your Mac to ensure you’ve got the most recent information.

Mac operating systems (OSes) and processing chips: Figuring out what you have

The process for wiping your Mac depends on a couple things: 

• What OS version you’re rocking
• What kind of processing chip you have

Fortunately, Apple has only made it easier to wipe your computer as the years and operating systems have rolled out. If you’re using macOS Monterey or later with an Apple-based processor chip, it’s very simple—you have the option to wipe your Mac from the System Settings. 

What macOS do I have?

You can see your current OS in the About This Mac screen (from the Apple menu in the upper-left corner of your screen, choose About This Mac), and below is a list of all OS releases you can compare against. You can also check out the Apple Help article on the topic. 

What kind of processing chip do I have in my Mac?

The second variable you need to know is what kind of processing chip you have in your Mac—an Apple-based chip (Apple M-series) or an Intel chip.

In November 2020, Apple launched its first Macs equipped with M1 chips, replacing the Intel-based processors of the past. The evolution of the M-series Apple chips has been notable largely for performance enhancements, but given that (at the time of publishing) this was four years ago, there’s a good chance that many users will have an Intel processor. 

To see what kind of chip you have, follow the same instructions as above—go to your Apple menu and select About This Mac. If you have an M-series chip, you’ll see that listed as marked in the screenshot below.

If you have an Intel-based Mac, you will see Processor, followed by the name of an Intel processor.

How to wipe your Mac

Okay, so now that you know your operating system and processing chip, we can get to the actual how-to of how to wipe your Mac. The steps will be slightly different based on each of the above variables. Let’s dig in. 

Wipe a Mac with an Apple chip and a recent macOS update

If you have macOS Monterey or later with an Apple chip, then you’re going to wipe your Mac using the Erase All Content and Settings function. (You might also see this called the Erase Assistant in Apple’s Help articles.) This will delete all your data, including iCloud and Apple logins, Apple wallet information, Bluetooth pairings, fingerprint sensor profiles, and Find My Mac settings, as well as resetting your Mac to factory settings. Here’s how you find it. 

If you have macOS Ventura or Sonoma: 

1. Select the Apple menu.
2. Choose System Settings. 
3. Click General in the sidebar. 
4. Click Transfer or Reset on the right. 

If you have macOS Monterey:

1. Select the Apple Menu. 
2. Choose System Preferences. 

Once the System Preferences window is open, select the dropdown menu in your top navigation bar. Then, select Erase All Content and Settings.

Once you’ve reached this point, then the steps will be the same for each process. Here’s what to expect. 

1. You’ll be prompted to log in with your administrator credentials. 
2. Next, you will be reminded to back up via Time Machine. Remember that if you choose this option, you’ll want to back up to an external device—because, of course, you’re about to get rid of all the data stored on this computer. 
3. Click Continue to allow all your settings, data, accounts, etc. to be removed.

4. If you’re asked to sign out of Apple ID, enter your Apple password and hit Continue. 
5. Click Erase all Content & Settings to confirm. 

6. Your Mac will automatically restart. If you have an accessory like a Bluetooth keyboard, you’ll be prompted to reconnect that device. 
7. Select a WiFi network or attach a network cable. 
8. After joining a network, your Mac activates. Click Restart. 
9. After your device has restarted, a setup assistant will launch (just like when you first got your Mac). 

It’ll be pretty clear if you don’t meet the conditions to erase your drive using this method because you won’t see Erase All Content and Settings on the System Settings we showed you above. So, here are instructions for the other methods. 

How to wipe a Mac with an Apple chip using Disk Utility

Disk Utility is exactly what it sounds like: a Mac system application that helps you to manage your various storage volumes. You’d use it to manage storage if you have additional storage volumes, like a NAS or external hard drive; to set up a partition on your drive; to create a disk image (basically, a backup); or to simply give your disks a check up if they’re acting funky. 

You can access Disk Utility at any time by selecting Finder > Go > Utilities, but you can also trigger Disk Utility on startup as outlined below. 

1. Turn on your Mac and continue to press and hold the power button until the startup options window comes up. Click Options, then click Continue.
2. You may be prompted to log in with either your administrative password or your Apple ID.
3. When the Utilities window appears, select Disk Utility and hit Continue.

4. If you’d previously added other drives to your startup disk, click the delete volume button (–) to erase them. 
5. Then, choose Macintosh HD in the sidebar. 
6. Click the Erase button, then select a file system format and enter a name for it. For Macs with an M1 chip, your option for a file system format is only Apple File System (APFS).
7. Click Erase or, if it’s an option, Erase Volume Group. You may be asked for your Apple ID at this point. 
8. You’ll be prompted to confirm your choice, then your computer will restart. 
9. Just as in the other steps, when the computer restarts, it will attempt to activate by connecting to WiFi or asking you to attach a network cable. 
10. After it activates, select Exit to Recovery Utilities. 

Once it’s done, the Mac’s hard drive will be clean as a whistle and ready for its next adventure: a fresh installation of the macOS, being donated to a relative or a local charity, or just sent to an e-waste facility. Of course, you can still drill a hole in your disk or smash it with a sledgehammer if it makes you happy, but now you know how to wipe the data from your old computer with much less ruckus.

How to wipe a Mac with an Intel Processor using Disk Utility

Last but not least, let’s talk about how to wipe an Intel-based Mac. 

1. Starting with your Mac turned off, press the power button, then immediately hold down the command (⌘) and R keys and wait until the Apple logo appears. This will launch macOS Recovery. 
2. You may be prompted to log in with an administrator account password. 
3. When the Recovery window appears, select Disk Utility.
4. In the sidebar, choose Macintosh HD.
5. Click the Erase button, then select a file system format and enter a name for it. Your options for a file system format include APFS, which is the file system used by macOS 10.13 or later, and macOS Extended, which is the file system used by macOS 10.12 or earlier.
6. Click Erase or Erase Volume Group. You may be prompted to provide your Apple ID. 
7. If you previously used Disk Utility to add other storage volumes, you can erase them individually using the process above. 
8. When you’ve deleted all your drives, quit Disk Utility to return to the utilities window. You may also choose to restart your computer at this point. 

Do you still need to know what kind of drive you have?

Wiping your Mac used to depend on what kind of drive you had—a hard disk drive (HDD) or solid state drive (SSD). As we’ve outlined above, today, the process depends on your OS and the type of chip you have. But some of you may have very old Macs you want to get rid of. Here we’ll talk a bit about HDDs vs SSDs and the impact that has on how you erase your computer. 

Around 2010, Apple started moving to only SSD storage in many of its devices. That said, some Mac desktop computers continued to offer the option of both SSD and HDD storage until 2020, a setup they called a Fusion Drive. The Fusion Drive is not to be confused with flash storage, a term that refers to the internal storage that holds your readily available and most accessed data at lower power settings. 

Note that as of November 2021, Apple does not offer any Macs with a Fusion Drive. Basically, if you bought your device before 2010 or you have a desktop computer from 2021 or earlier, there’s a chance you may be using an HDD. 

So, what kind of drive do you have?

To determine what kind of drive your Mac uses, click on the Apple menu and select About This Mac. 

Avoid the pitfall of selecting the Storage tab in the top menu. What you’ll find is that the default name of your drive is “Macintosh HD” which is confusing, given that they’re referring to the internal storage of the computer as a hard drive when (in most cases), your drive is an SSD. While you can find information about your drive on this screen, we prefer the method that provides maximum clarity. 

So, on the Overview screen, click System Report. Bonus: You’ll also see what type of processor you have and your macOS version (which will be useful later). 

Once there, select the Storage tab, then the volume name you want to identify. You should see a line called Medium Type, which will tell you what kind of drive you have.

Securely erasing drives: Questions and considerations

Some of you drive experts out there might remember that there is some nuance to security when it comes to erasing drives, and that there are differences in erasing HDDs versus SSDs. Without detouring into why and how that’s the case, just know that on Fusion Drives or Intel-based Macs, you may see additional security options you can enable when erasing HDDs. 

There are four options in the “Security Options” slider. “Fastest” is quick but insecure—data could potentially be rebuilt using a file recovery app. Moving that slider to the right introduces progressively more secure erasing. Disk Utility’s most secure level erases the information used to access the files on your disk, then writes zeros across the disk surface seven times to help remove any trace of what was there. This setting conforms to the DoD 5220.22-M specification. Bear in mind that the more secure method you select, the longer it will take. The most secure methods can add hours to the process. For peace of mind, we suggest choosing the most secure option to erase your hard drive. You can always start the process in the evening and let it run overnight.

After the process is complete, restart your Mac and see if you can find any data. A quick inspection is not foolproof, but it can provide some peace of mind that the process finished without an interruption. 

Securely erasing SSDs and why not to

If your Mac comes equipped with an SSD, Apple’s Disk Utility software won’t actually let you zero the drive. Sounds strange, right? Apple’s online Knowledge Base explains that secure erase options are not available in Disk Utility for SSDs.

Fortunately, you are not restricted to using the standard erasure option to protect yourself. Instead, you can use FileVault, a capability built into the operating system.

Encrypting your computer with FileVault

FileVault is an excellent option to protect all of the data on a Mac SSD with encryption. FileVault is whole-disk encryption for the Mac. With FileVault engaged, you need a password to access the information on your hard drive. Even without it, your data is encrypted and it would be very difficult for anybody else to access.

Before you use FileVault, there is a crucial downside. If you lose your password or the encryption key, your data may be gone for good! 

When you first set up a new Mac, you’re given the option of turning FileVault on. If you don’t do it then, you can turn on FileVault at any time by clicking on your Mac’s System Preferences, clicking on Security & Privacy, and selecting the FileVault tab. Be warned, however, that the initial encryption process can take hours, as will decryption if you ever need to turn FileVault off.

With FileVault turned on, you can restart your Mac into its Recovery System following the directions above and erase your hard drive using Disk Utility, once you’ve unlocked it (by selecting the disk, clicking the File menu, and clicking Unlock). That deletes the FileVault key, which means any data on the drive is useless.

Nowadays, most Macs manage disk encryption through the T2 chip and its Secure Enclave, which is entirely separate from the main computer itself. This is why FileVault has no CPU overhead—it’s all handled by the T2 chip. Although FileVault doesn’t impact the performance of most modern Macs, we’d suggest only using it if your Mac has an SSD, not a conventional HDD.

Securely erasing free space on your SSD

If you don’t want to take Apple’s word for it, if you’re not using FileVault, or if you just want to, there is a way to securely erase free space on your SSD. It’s a little more involved, but it works. Before we get into the nitty-gritty, let me state for the record that this really isn’t necessary to do, which is why Apple’s made it so hard to do.

To delete all data from an SSD on an Apple computer, use Apple’s Terminal app. Terminal provides you with command line interface (CLI) access to the OS X operating system. Terminal lives in the Utilities folder, but you can access Terminal from the Mac’s Recovery System. Once your Mac has booted into the Recovery partition, click the Utilities menu and launch Terminal.

From a Terminal command line, type the following:

diskutil secureErase freespace VALUE /Volumes/DRIVE

That tells your Mac to securely erase the free space on your SSD. You’ll need to change value to a number between 0 and 4. Zero is a single-pass run of zeroes, 1 is a single-pass run of random numbers, 2 is a seven-pass erase, 3 is a 35-pass erase. Finally, level 4 is a three-pass erase with random fills plus a final zero fill. drive should be changed to the name of your hard drive. To run a seven-pass erase of your SSD drive in JohnB-MacBook, you would enter the following:

diskutil secureErase freespace 2 /Volumes/JohnB-MacBook

Note that while Mac’s Terminal typically uses forward slashes ( / ), if you have a space in the name of your hard drive, you’ll see a backslash ( \ ) to indicate that break in syntax. (So “Macintosh HD” becomes /Macintosh\ HD.) For example, to run a 35-pass erase on a hard drive called Macintosh HD, enter the following:

diskutil secureErase freespace 3 /Volumes/Macintosh\ HD

If you’re like the majority of computer users, you’ve never opened your Terminal application—and that’s probably a good thing. If you’re providing the proper instructions, a CLI lets you directly edit the guts of your computer. If you’re not providing the proper instructions, things will just error out, and likely you won’t know why. 

In conclusion, in most cases, it’s simple to wipe your Mac hard drive

All this to say: Apple has made specific choices about designing products for folks who aren’t computer experts, and in most cases, you won’t need to break out the CLI knowledge to securely erase your hard drive. While Mac sometimes limits how customizable you can get on your device (i.e. it’s super hard to zero out an SSD), it’s usually for good reason—in this case, it’s to preserve the health of your drive in the long term. So, if you personally are planning to reuse the device you’re wiping, or if you’re not being targeted in a real-life James Bond movie, in most instances, it’s a less-than-ten step process to securely wipe your Mac and send it on to a new, shiny future. 

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