In this article we're going to show yous how to perform a clean install of macOS. There are a number of reasons why you might want to do a make clean install:

  • You lot might desire to reinstall the operating organization in social club to correct problems with your Mac - doing a clean install may exist a good option if your Mac is running slow or otherwise misbehaving.
  • Doing a clean install allows yous to clear away old files that you might have been accumulating for years earlier installing the operating system onto a freshly formatted disk.
  • A make clean install is also something you should do before selling your Mac or passing it on. It allows yous to remove all your data from your Mac and return it to factory settings for next person.
  • A clean install is as well something many estimator users resort to when they are trying to go rid of a virus (although in that location is a lot of debate about whether there are viruses on the Mac).

Whatever your reason, a clean install of macOS might solve a lot of problems.

However, things have changed in recent years that mean that a make clean install may not be necessary, so nosotros will start by explaining why you might not demand to do a clean install on your Mac.

You should besides keep in mind that there are multiple ways to do a clean installation of macOS. The traditional mode was to make a bootable copy of the macOS installer on a USB stick and then reformat your drive before installing the bootable re-create on to your Mac. At that place is also an even simpler method that allows yous to utilize macOS Recovery to reinstall the Mac operating arrangement over the web (we take a split tutorial about doing a clean install of macOS using Recovery). Plus, if you lot are running macOS Monterey on a M1 Mac or an Intel Mac with a T2 chip then in that location is a new setting in Arrangement Preferences that makes wiping your Mac easier than ever. We'll run through all of these methods below.

Should I do a clean install on my Mac?

In the by it was helpful to reinstall the organization if you lot wanted to correct some Mac issues, but today this solution doesn't make as much sense.

Since macOS Big Sur, macOS has its home on its own book, which is both read-only and cryptographically signed and sealed (referred to every bit a Sealed System Volume). This seal is stored either in the T2 flake of the newer Intel Macs or in the Secure Enclave of the Apple M1.

Each component of the system is signed in hierarchical club, and whatsoever change to a component would also invalidate the seal that represents the top level. For further security, these Macs also do non start directly from the system volume, but from a snapshot of the system. And snapshots cannot be changed, fifty-fifty by the system itself.

And so macOS itself cannot exist inverse by whatsoever software that you install as a user. Should a problem occur with macOS during a restart, perchance because a storage infinite on the SSD is defective and thus a organization component is no longer intact, this will be recognised past the startup process since the seal volition at present be invalid. Should this happen you will have to reinstall the organization.

However, if your Mac boots upwardly without event so it indicates that there are no bug with the arrangement. Equally long as your Mac works (which can be adamant on the footing of the seal), the Mac is considered to be in working gild as information technology complies with Apple's specifications.

For that reason, fifty-fifty if you do encounter problems on Macs with T2 fleck or Apple Silicon while running macOS Big Sur or macOS Monterey, it makes no sense to reinstall the system yourself.

For those who want to practice a clean install so that no leftovers that belong to an old system are carried along, this no longer applies considering none of this information is carried over. All components are checked after installation, then signed and finally the unabridged system sealed again. Again, the seal guarantees that everything is fine and that nothing untoward has crept in.

Yet, there is one component of the organization software that is non installed on the read-only system volume. All other user-installed programs reside on the volume with the user information, including Safari. This ways Apple tree tin offering a separate update for the browser and WebKit, and so that you lot practise non have to reinstall the whole system each time.

In the case of Safari and other apps in that location tin can be benefits in cleaning upwards your Library folder since it may still contain remnants of old applications you no longer utilize.

If you feel that you have a lot of this sort of crud on your Mac then cleaning your bulldoze could be useful, simply exist prepared that it can be a risky business and yous may end up deleting something important. Beware that a make clean install tin can cause more problems that it fixes.

Yous might prefer to apply an application like CleanMyMac X from MacPaw (£34.95/$39.95 a year, free trial), or ane of these alternatives: Best Mac Cleaner App.

If you lot are happy to have the chance and still desire to wipe your Mac and reinstall macOS - which yous should definitely do if you lot are selling or passing on your Mac - read on!

How to wipe your Mac and reinstall macOS

As nosotros explained in a higher place, there is more than one mode to wipe your Mac and reinstall macOS:

  • Make a re-create of the macOS installer on a USB stick, reformat your drive and then install the macOS on to your Mac from the installer.
  • Use macOS Recovery to reinstall macOS the spider web.
  • Use the new Erase All Content and Settings option setting in System Preferences (available if yous are running macOS Monterey on a M1 Mac or an Intel Mac with a T2 chip).

Non only are there three different methods (which nosotros'll run through below) the methods depend on the version of macOS that you are running.

There is besides the even trickier business organization of installing a make clean copy of an older version of macOS on your Mac (Big Sur, Catalina, High Sierra, Sierra, El Capitan, Mojave, Yosemite or an even old version of OS 10). Speaking of which, if an old version is what y'all're looking for, information technology may be worth taking a look at another article where we focus on that entirely: How to download and install old versions of Bone X on a Mac.

Before you lot begin...

We recommend that you make a back upward, only in case something goes wrong. Total instructions hither: How to back up a Mac.

Annotation that with regard to backups, yous probably won't want to recover a Time Machine fill-in if y'all don't desire to copy over all the setting and preferences associated with your quondam system. You could alternatively sync all your Documents and Desktop with iCloud rather than run a full backup, but make sure that everything you need is in the deject and be aware that you may lose system setting and applications.

Ready? Let'due south become started.

How to clean install macOS Monterey

How to clean install macOS Monterey

Before the arrival of Monterey it was necessary to create a bootable USB drive or utilise Recovery Mode to wipe your disk. However, with Monterey Apple tree has fabricated it easy to get a factory-fresh installation.

There is a new Erase All Content and Settings option in the Organization Preferences menu of Monterey that volition allow you to reset your Mac to factory settings without having to work through the many steps to wipe and format your drives.

As well as macOS Monterey, you demand to have a M1 Mac, or an Intel Mac with a T2 chip within.

These Intel Macs have the T2 security chip:

  • MacBook Air from 2022
  • MacBook Pro from 2022
  • Mac mini from 2022
  • iMac 27-inch from 2022
  • iMac Pro
  • Mac Pro from 2022

If yous have the Erase All Content and Settings option in Monterey then you can easily wipe your organization, remove all your data and user-installed applications and start from scratch. Here'southward what you need to do:

  1. Open Organization Preferences.
  2. Click on System Preferences in the menu bar at the top of your screen.
  3. Click on Erase All Content and Settings.
  4. Enter your password.
  5. (You'll exist reminded to do a backup with Time Machine before you begin deletion - but you can skip that step.)
  6. A window will show y'all what will be deleted, including Apple ID, Bear upon ID, accessories, and Find My settings.
  7. Finally you volition need to log out of your Mac and all related services using your Apple ID.
  8. Before your Mac is erased you receive a final warning, so if you have second thoughts at least you lot can cease at this bespeak! Erase Mac Monterey
  9. Having clicked the second Erase All Content & Settings your Mac will restart. Somewhen you volition encounter a black screen while it restarts.
  10. Once your Mac restarts you can go through the steps to set it upward equally new, or you can leave it at this phase for the adjacent owner to ready up. Simply turn the Mac off first.

How to do a clean install via Recovery

How to do a clean install via Recovery

We explain how to reinstall macOS via Recovery here: How to reinstall macOS, but we will summarise the steps hither.

How you enter recovery style depends on the Mac you own.

If you want to enter recovery mode on an M1 Mac you lot need to press and concur the ability push button when you start up your Mac and continue to printing and concord the push until you encounter a startup options window appear with an Options icon. Select Options and click Continue.

To enter Recovery on an Intel Mac press Command+R.

  1. Once Recovery starts upward you'll see a macOS Utilities window with options to Restore From Fourth dimension Car Fill-in, Reinstall macOS [version], Safari (or Go Help Online in older versions) and Disk Utility. If you lot want to wipe the Mac before reinstalling choose Disk Utility.
  2. Run through the steps to erase your Mac equally detailed in the How to reinstall macOS guide.
  3. After you have erased your drive click on Disk Utility > Quit Disk Utility. Or just Command + Q.
  4. Now cull Reinstall macOS from the options.
  5. Wait while macOS is reinstalled. Expect this to have a while.

How to clean install macOS using a bootable USB

How to clean install macOS using a bootable USB

Now for the method that involves using a bootable USB with the macOS installation on it. This might be the best method if you lot already take the installation files downloaded and don't want to wait for hours for Recovery to download the files.

Before y'all begin y'all'll need the following:

  • A 15GB or larger removable USB flash drive to hold the installer file for our chosen version of macOS. (Nosotros're going to erase it, and then make sure it doesn't contain whatsoever valuable data.)
  • Admin privileges for the Mac.
  • A back up, just in instance something goes wrong.

Pace 1: Format the external drive

Step 1: Format the external drive

We're going to re-download the installer file for our chosen version of macOS and shop it on a USB stick or external drive. Merely before you do that you tin can prepare the USB drive by reformatting it.

Here'southward how to format your USB drive correctly:

  1. Plug in the USB bulldoze.
  2. Get to Applications > Utilities.
  3. Open Disk Utility.
  4. Select the drive and click Erase. (The proper name of the disk needs to be "Untitled", if the Final commands below are to work, then rename it if necessary.)
  5. Select Mac Bone Extended (Journaled) as the format blazon.
  6. Choose GUID Partition Map from the Scheme options (if you don't see this you are in the incorrect view - you lot need to select the external drive, not the container below information technology).
  7. Click Erase.
  8. Disk Utility volition create the partition and ready the drive (it tin take a while).
  9. Click Done.

Step 2a: Get the macOS install file

Step 2a: Get the macOS install file

If y'all're reinstalling the latest version of macOS, or installing a new version of macOS, the adjacent step is relatively easy although the process for obtaining the installer will exist different.

If you are currently running Big Sur and desire to exercise a clean install of macOS Monterey (in one case it arrives) then you can download the installation package via Organisation Preferences.

  1. Open up Organization Preferences.
  2. Choose Software Update.
  3. Download the Monterey install files.

If, on the other manus, you desire to reinstall Big Sur and are already running Large Sur the best way to admission the installer for Large Sur is via the Mac App Shop. Here's a link to Big Sur on the Mac App Shop. If it's Catalina you lot want you can go that here. Alternatively open Mac App Store and search for the version yous want.

Once y'all have located the version of macOS yous want on the Mac App Shop follow these instructions:

  1. Hit Download or Go (depending on the version of the Mac App Store y'all are using).
  2. You may get a alarm message at this bespeak, telling yous that this version of macOS 'is already installed on this computer. Would y'all like to proceed?' Click Continue.
  3. Enter your Apple tree ID and password.
  4. The Catalina install files will start to download.

The installer file will be multiple GB. Big Sur is 12.6GB, for example, and then wait downloading to have a while.

The adjacent step is worth highlighting for what you shouldn't practise, rather than what you should do:

  1. When the macOS installer has finished downloading the installer will launch automatically, but we don't want to employ it even so and then don't click to start the installation!
  2. Press Control + Q to quit out of the installer.
  3. Observe the installer file (information technology will be located in your Applications folder, or you could search for it using Spotlight (control + Space and first typing Monterey, Catalina or Big Sur).

If you just want to install Monterey you lot can skip the next stride where we'll exist showing how to dig up the installer file for an older version of macOS or Mac OS X.

Step 2b: Get the install file for an older version of macOS

Step 2b: Get the install file for an older version of macOS

For older versions of macOS and Mac OS X it'due south a bit more than difficult to get the install file: Apple doesn't offer downloads of outdated OS versions through the normal store front, and searching for the name won't find what you're looking for.

We have a detailed guide to getting older versions of macOS hither, only we will explain what you need to do below.

Depending on the version of macOS you are running, the installers for some versions of macOS can be found in the Purchased section of the App Store.

Log into the Mac App Shop with the Apple ID you used and click Purchased in the carte du jour bar along the top. Scan down the listing of apps you've purchased or download for free (which is in society of when you downloaded them) and find the name of your chosen version: El Capitan, Yosemite or whatsoever. Click download.

However, in that location are a few reasons why this may not piece of work for you:

  • If you have already installed Mojave, Catalina or Big Sur on your Mac you cannot easily search for old versions of macOS from the Mac App Store.
  • You won't find the version of macOS your Mac shipped with in the Purchased section of the App Shop.
  • And you lot won't find versions of macOS in the purchased section if yous never installed that version.

However, luckily it is nonetheless possible to get hold of some versions of macOS if you are running a newer version than Sierra.

  • Big Sur is on the Mac App Store hither.
  • Catalina is on the Mac App Store hither.
  • You can get macOS Mojave via this link.
  • Download High Sierra here.
  • Sierra is hither as a direct download.
  • El Capitan tin be downloaded from this link.
  • Yosemite is available here.

If you click to find Catalina, Mjave or High Sierra and the page doesn't open up in the Mac App Store try a couple of things: Make sure that the Mac App Store is closed earlier yous click the link; Cut and paste the link into Safari.

As in the step above, once you lot have downloaded the installer don't run it - only close the installer if it opens.

For more advice on getting hold of even older editions of Mac OS, seeHow to go quondam versions of OS X.

Pace three: Create a bootable USB deejay

Step 3: Create a bootable USB disk

Next we demand to turn out USB drive into a bootable USB disk so that we can utilise it to install a new copy of macOS on our Mac later on we have reformatted it (that step volition come up later in this tutorial).

We've got full instructions on How to make a bootable macOS install drive in a unlike commodity, merely nosotros'll run through the basics here.

We're going to create the bootable drive using Concluding, which you tin open on your Mac by pressing Control + Space bar and typing Terminal.

Connect the USB drive that y'all formatted before to your Mac. Make sure it's called Untitled - rename it if necessary (this will help you enter the correct text in Terminal in the next steps).

Creating a bootable installer has been pretty easy since the arrival of Mavericks in 2022 cheers to the Last command createinstallmedia that arrived in that version. Here's how to utilise it (note that the proper noun of the version of macOS will depend on which version you are installing):

  1. Open the Final awarding on your Mac (find it by searching using Command + Infinite and typing Terminal)
  2. Now copy and paste the following text into Last (This text is for Big Sur - we include the text needed for the other versions of macOS in this article). When you cut and paste the following text into Terminal do check that information technology maintains the -- as we accept heard of people pasting in the -- and it converting to –)
    sudo /Applications/Install\ macOS\ Monterey.app/Contents/Resource/createinstallmedia --volume /Volumes/MyVolume (where MyVolume is the name of the external drive you are using - it could be Untitled)
  3. Press Render.
  4. Enter your password (y'all won't see the password announced).
  5. Press Return again.
  6. Terminal will warn that it is most to erase the drive. If you want to go along printing Y and then Return. The process tin take a while, yous'll see "Erasing Disk: 0%… ten%… 20%… 30%…100%…
  7. Next Concluding will spend a few minutes copying the installer file to your drive. "Copying installer files to disk… Re-create complete" and then on will appear in the Terminal window. Again, this tin can have a while - it took our Mac ages to go from 0% to ten%...
  8. When the bootable drive is prepared you will see the word Washed. It can accept a while.

Now you have the installer on the external drive you lot can use that to install copies of macOS on multiple Macs - which could exist helpful if you are admin for a lot of systems.

However, if you are reading this because you lot want to practise wipe your Mac and do a clean install, read on...

Step 4: Wipe your Mac

Step 4: Wipe your Mac

Now nosotros are ready to install the copy of macOS from the installer drive on our Mac. If yous desire to do a fresh installation (and completely wipe your Mac) information technology's time to reformat your Mac's start-up drive.

Here'southward how to do a fresh installation of macOS if you lot aren't already running Catalina or Big Sur.

  1. Connect your boot bulldoze.
  2. Start up - or restart - your Mac while belongings downwardly the Option cardinal (also known as Alt). This will take you to Startup Manager.
  3. Choose to install your chosen version of macOS from the external drive.
  4. Select Disk Utility.
  5. Select your Mac'south start up disc, probably chosen Macintosh HD or Habitation.
  6. Click on Erase.
  7. Expect for your startup disk to be formatted.
  8. Go back to the main Utilities menu and cull Install macOS.
  9. Choose your startup bulldoze equally the location to install macOS.

Once installation is consummate, you can restore apps and settings from your fill-in, or download them once more manually.

How to erase your bulldoze in Catalina or Large Sur

Notation: if y'all are running macOS Catalina or Large Sur you will have 2 volumes: Macintosh Hd and Macintosh HD - Data. If you want to practice a clean install of Catalina or Big Sur over an existing installation of Catalina you volition demand to first delete the Macintosh HD - Data book. Nosotros cover how to exercise this in more than detail here: How to reset and wipe a Mac.

Macintosh HD - Information in Catalina/Big Sur is where your data is stored separately to the macOS installation.

  1. Either click on the - button or get to the menu and choose Edit > Delete APFS book.
  2. You will see a message alarm you that this volition permanently erase your data. Click on Delete. Do not choose Delete Volume Grouping.
  3. Wait while the volume is deleted.

Then you can move onto deleting your Macintosh HD volume equally above.

Stride 5: Install macOS

Step 5: Install macOS

Now you can use your bootable installer to do a clean install of macOS on your wiped Mac.

The process for installing the OS from the bootable installer is slightly different if you lot have an M1 Mac (also known as Apple Silicon) or an Intel processor inside your Mac. We'll run through both methods.

In both cases you will need to have your Mac connected to the Internet. It too needs to exist compatible with the version of macOS yous are trying to install (you can't install a macOS older than Big Sur on a M1 Mac).

How to install macOS from a bootable installer

If y'all accept an Intel-powered Mac here'south how to install macOS from a bootable installer:

  1. Plug in your bootable installer
  2. Turn off your Mac.
  3. Press and concord Choice/Alt while the Mac starts upward - keep pressing the fundamental until yous run into a screen showing the bootable book.
  4. Choose the bootable installer volume.
  5. Click Continue.
  6. Select Install macOS from the Utilities window that appears.
  7. Click Continue.
  8. Now follow the onscreen instructions to practice your clean install.

If you accept an M1 Mac hither'southward how to install macOS from a bootable installer. As we mentioned above, you can't install a macOS older than Big Sur on a M1 Mac.

  1. Plug in your bootable installer
  2. Plow off your Mac.
  3. Press the power button to turn on the Mac - but keep it pressed until you run into the startup options window including your bootable volume.
  4. Choose the bootable installer volume.
  5. Click Proceed.
  6. The macOS installer should open - when it does follow the onscreen instructions to do the clean install.