Apple today released macOS 12 Monterey, and whenever a new operating system is released for the Mac, some users prefer to perform a clean installation. This article explains how to perform what is effectively a clean install of Monterey using a brand new option that's available on Apple silicon-powered Macs and Intel Macs with a T2 security chip.

Monterey Mac as External Monitor Feature
Clean installing macOS is often done to remove annoying quirks and strange behaviors that a Mac may have inherited over time, and can also help to reclaim disk space caused by junk files left by third-party apps. However, even if neither of these issues have arisen for you, sometimes it's just nice to start afresh for that "brand new Mac" feeling and then migrate your apps, documents, and data, either manually, or by migrating from a Time Machine backup.

Clean installing previous versions of macOS usually involves creating a bootable copy of the macOS installer on a flash drive or USB stick and then reformatting your drive before installing the bootable copy on your Mac, or using macOS Recovery to reinstall the Mac operating system over an internet connection. In Monterey, however, a third option has come into play on newer Macs that offers a very simple and straightforward way to erase your Mac without needing to reinstall the operating system.

Following in the footsteps of the iPhone and iPad, Apple silicon Macs and Intel Macs with a T2 security chip (2017-2020 models) now have an "Erase All Content and Settings" option available in macOS Monterey. Because storage is always encrypted on Mac systems with Apple silicon or the T2 chip, the system is instantly and securely "erased" by destroying the encryption keys.

erase Mac
Not only does this effectively erase all user data and user-installed apps from your Mac without reinstalling macOS, it also signs out your Apple ID, removes your Touch ID fingerprints, purchases, and all Apple Wallet items, and turns off Find My and Activation Lock, making it far easier to restore your Mac to like-new factory settings.

This ability means you can simply download and install ‌macOS Monterey‌ over your current macOS version when prompted, and then select the new erase function in Monterey, which will erase your Mac and leave the core macOS system intact. After erasing the Mac, it will display the Setup Assistant and be ready to be set up like new. You can then migrate your data manually or by using the Setup Assistant's migration option. The following walkthrough breaks down the steps involved.

  1. Before you do anything else, back up your data using Time Machine or your preferred backup method.
  2. In macOS, click the Apple () symbol in the menu bar and select System Preferences.
  3. Click Software Update in the preferences pane.
    macOS

  4. Allow Software Update to ping Apple's servers, then click Upgrade Now to download the Monterey installer when it appears. You can continue to use your Mac while the installer is being downloaded. Once the installer has downloaded, you'll receive a prompt. Click to install the new version of macOS and wait for the installation to complete.
    software update

  5. Once your Mac has restarted into Monterey, click the Apple () symbol in the menu bar and select System Preferences....
  6. When the preferences pane appears, select System Preferences -> Erase All Content and Settings from the menu bar.
    macOS

  7. Enter your admin password in the Erase Assistant dialog prompt and click OK.
  8. Note all the settings, data, media, and other items that will be removed. Click Continue if you're sure.
    erase Mac

  9. Click to sign out of your ‌Apple ID‌, then click Erase All Content & Settings in the prompt to confirm.
    erase mac

  10. Allow the erase process to complete. Your Mac may restart more than once during the process, after which you may be prompted to activate your Mac over Wi-Fi.
  11. Once finished, you'll see the "hello" message on your Mac's screen, indicating the Setup Assistant is ready. Follow the onscreen instructions, and if desired, elect to migrate your data from a Time Machine backup when the option appears.
    hello Mac

That's all there is to it. Even if you're not clean installing Monterey today, the new option makes it far more convenient to restore your Mac to factory settings, whether you simply want to start afresh with your Mac in future or plan to sell or gift it to another person.

Related Roundup: macOS Monterey
Related Forum: macOS Monterey

Top Rated Comments

kalsta Avatar
9 months ago

Clean installing macOS is often done to remove annoying quirks and strange behaviors that a Mac may have inherited over time, and can also help to reclaim disk space caused by junk files left by third-party apps. However, even if neither of these issues have arisen for you, sometimes it's just nice to start afresh for that "brand new Mac" feeling and then migrate your apps, documents, and data, either manually, or by migrating from a Time Machine backup.
Good luck with that. Migrating from a Time Machine backup will restore your Library folder, along with all those 'junk files' you just got rid of. A real clean install is not for the faint-hearted! I've done it several times over the years and should probably write a book about it. Possibly worth it if your Mac is behaving poorly. Definitely not worth it for 'that "brand new Mac" feeling'.
Score: 19 Votes (Like | Disagree)
TriBruin Avatar
9 months ago

This is not really a clean install, to be fair. You might end up in the same state, settings and user created files wise, but I’m not sure it’s an equivalent of formatting a partition and installing macOS on it from scratch.

Regardless, this is not Windows, so this should be more than enough.
Nope, this is a clean install. NOTHING related to the user is left on the drive. The reason this works is that starting with Catalina, Apple split the O/S volume from the Data volume. With Big Sur, Apple took one stop further and has cryptographically signed the O/S volume to prevent modification. In addition, during regular operation, the system volume is copied to a disk image and run from there. You are never running the system directly from the O/S volume.

Erasing the drive clears the encryption keys for the data volume, rendering it unusable. The system then recreates the data volume and activates the O/S.
Score: 12 Votes (Like | Disagree)
IamTimCook Avatar
9 months ago
I do this with every Major OS update and seem to never get those “unique” quirky issues that others complain about… Bluetooth, display sleep/connection, audio, etc.
Score: 7 Votes (Like | Disagree)
Kylo83 Avatar
9 months ago
I would rather fresh install, this will still keep main files that could be corrupted
Score: 7 Votes (Like | Disagree)
kalsta Avatar
9 months ago

I was so excited reading the headline, but then my hopes were dashed since I have a 2015 iMac. I have some quirks that I'd like to try and get rid of by doing a clean install, so I guess it's the old-school method for me. If they release that iMac with M2 or M1 Pro/Max (and space gray please!), then I'll leave the old-school method behind!
Erasing macOS was never the hard bit. Sure, the real 'old-school method' of creating a bootable installer was a little bit of effort, but installing from macOS Recovery is a doddle. See How to reinstall macOS ('https://support.apple.com/en-au/HT204904'). The hard bit is restoring your Mac to the way you like it without copying over all the old Library files.
Score: 6 Votes (Like | Disagree)
Apple_Robert Avatar
9 months ago

I must be getting old. To me Clean Install is basically wiping the drive and reinstalling Mac OS for DISK, Another bootable external volume or Net Boot, Shift options command R. Am i right or just a ghost in the past. lol
I am used to old school as well. Monterey changed that for me and I am so glad I don't have to do the old school route any more.
Score: 3 Votes (Like | Disagree)

Related Stories

2018 2018 macbook pro battery

How to Show Battery Percentage in Your Mac's Menu Bar

Wednesday March 2, 2022 8:09 pm PST by
If you're the sort of person who likes to know exactly how much battery life your MacBook Pro or MacBook Air has left, then you'll want macOS to show the percentage next to the battery level icon in the menu bar. This article explains how. If you look at the right-hand side of the menu bar in macOS Monterey, you'll notice a battery level icon indicating the amount of charge your Mac has...
macOS Monterey FaceTime Portrait Mode

How to Blur Your Background on a FaceTime Call on Mac

Thursday December 16, 2021 1:50 pm PST by
In macOS Monterey, Apple brought several enhancements to FaceTime on Mac, including new visual and audio effects to improve the video call experience. One of the new visual features is Portrait mode in calls. With this mode enabled, you can blur your background so that the focus is on you rather than what's behind you. The feature is commonly used by other video conferencing apps like...
apple studio display blue

How to Check and Update Your Apple Studio Display's Firmware

Tuesday March 22, 2022 10:37 am PDT by
Computer monitors and displays don't typically receive firmware updates, but Apple's 27-inch 5K Studio Display isn't typical. That's because it contains its own dedicated A13 processor (the same chip Apple used in the iPhone 11) and runs a full version of iOS, which powers the audio output and deals with webcam processing. The inclusion of a dedicated computer processor means Apple can issue ...
Universal Control Colored Feature

How to Use Universal Control Across Macs and iPads

Monday February 7, 2022 1:04 pm PST by
As of iPadOS 15.4 and macOS Monterey 12.3, Apple has introduced support for Universal Control, the long-awaited feature that's designed to allow multiple Macs and iPads to be controlled with a single mouse and keyboard. Thanks to Universal Control, you can use the same cursor and keyboard on any nearby Mac or ‌iPad‌ that's signed into your iCloud account. So, for example, if you have a...
passwords system preferences

macOS 12.3: How to Add Notes to iCloud Keychain Entries

Tuesday February 8, 2022 3:07 pm PST by
In macOS Monterey 12.3, currently in beta, Apple has added the ability for users to add notes to account entries in iCloud Keychain. This article explains how it's done. Slowly but surely with each iteration of macOS, Apple has been improving ‌iCloud‌ Keychain to put it on equal footing with rival third-party password managers such as 1Password. And in macOS 12.3, it continues that...
apple studio display blue

How to Use Siri on Apple's Studio Display

Wednesday March 23, 2022 7:20 pm PDT by
Apple's Studio Display comes with three built-in microphones that allows it to recognize "Hey Siri" voice commands and respond to spoken queries, and the connected Mac doesn't even have to officially support Siri for it to work. Keep reading to learn how. While Siri support has been available on most recent Macs for some time, some Macs such as the 2019 Mac Pro and Mac mini (2018 and later)...
universal control wwdc

How to Set Up Universal Control Between Mac and iPad

Friday January 28, 2022 10:40 am PST by
As of iPadOS 15.4 and macOS Monterey 12.3, Apple has introduced support for Universal Control, the long-awaited feature that's designed to allow multiple Macs and iPads to be controlled with a single mouse and keyboard. Thanks to Universal Control, you can use the same cursor and keyboard on any nearby Mac or ‌iPad‌ that's signed into your iCloud account. So, for example, if you have a...
Universal Control Colored Feature

How to Adjust or Disable Universal Control on Mac

Tuesday March 15, 2022 7:26 am PDT by
As of iPadOS 15.4 and macOS Monterey 12.3, Apple has introduced support for Universal Control, the long-awaited feature that's designed to allow multiple Macs and iPads to be controlled with a single mouse and keyboard. Thanks to ‌Universal Control‌, you can use the same cursor and keyboard on any nearby Mac or ‌iPad‌ that's signed into your iCloud account. So, for example, if you...

Popular Stories

macbook air m2

Exclusive: Apple Plans to Launch MacBook Air With M2 Chip on July 15

Wednesday June 29, 2022 5:23 pm PDT by
The redesigned MacBook Air with the all-new M2 Apple silicon chip will be available for customers starting Friday, July 15, MacRumors has learned from a retail source. The new MacBook Air was announced and previewed during WWDC earlier this month, with Apple stating availability will begin in July. The MacBook Air features a redesigned body that is thinner and lighter than the previous...
Mac Studio IO

Apple Begins Selling Refurbished Mac Studio Models

Thursday June 30, 2022 7:42 pm PDT by
Apple today began selling refurbished Mac Studio models for the first time in the United States, Canada, and select European countries, such as Belgium, Germany, Ireland, Spain, Switzerland, the Netherlands, and the United Kingdom. In the United States, two refurbished Mac Studio configurations are currently available, including one with the M1 Max chip (10-core CPU and 24-core GPU) for...
top stories 2jul2022

Top Stories: M2 MacBook Air Release Date, New HomePod Rumor, and More

Saturday July 2, 2022 6:00 am PDT by
The M2 MacBook Pro has started making its way into customers' hands and we're learning more about how it performs in a variety of situations, but all eyes are really on the upcoming M2 MacBook Air which has seen a complete redesign and should be arriving in a couple of weeks. Other top stories this week included a host of product rumors including additional M2 and even M3 Macs, an updated...
original iphone 2007

15 Years Ago Today, the iPhone Went On Sale

Wednesday June 29, 2022 4:43 am PDT by
Fifteen years ago to this day, the iPhone, the revolutionary device presented to the world by the late Steve Jobs, officially went on sale. The first iPhone was announced by Steve Jobs on January 9, 2007, and went on sale on June 29, 2007. "An iPod, a phone, an internet mobile communicator... these are not three separate devices," Jobs famously said. "Today, Apple is going to reinvent the...
rootbug

Major macOS High Sierra Bug Allows Full Admin Access Without Password - How to Fix [Updated]

Tuesday November 28, 2017 12:33 pm PST by
There appears to be a serious bug in macOS High Sierra that enables the root superuser on a Mac with a blank password and no security check. The bug, discovered by developer Lemi Ergin, lets anyone log into an admin account using the username "root" with no password. This works when attempting to access an administrator's account on an unlocked Mac, and it also provides access at the login...