Factory resetting a Mac is a rather involved process that in essence requires you to start the machine in Recovery Mode, erase the hard drive using Disk Utility and then reinstall macOS. However, if you're passing on an old Mac to family or friends, selling your machine, or simply looking to fix a misbehaving Apple computer, wiping your Mac can also be a necessary process.
Fortunately it's easy to remove all the data and content from a Mac before you sell it on, and it's very important that you do so if you don't want to leave yourself open to identity theft. Just remember that if you're passing on an old Mac, removing personal information alone isn't enough - you also need to make sure there's a working version of macOS installed after the wiping is complete for the next owner to use.
Our guide to wiping all your data from a Mac enables you to reset your machine to an unblemished factory state, as if it was fresh out of the box, with a clean and working install of macOS. If you've forgotten the password, you may wish to read How to reset a Mac without the password instead. (Or read our guide to deleting or resetting an iPhone or iPad if you want to wipe one of those devices.)
In brief, here is how to reset your Mac. Further detail is given below and linked from each step.
- Make sure you're connected to the internet so you can download the latest copy of the Mac operating system able to run on your machine. This is likely to be macOS Mojave, but an older Mac may need an older version of Mac OS X (we explain how to obtain one here).
- Either back up your Mac using Time Machine or clone your internal hard drive to an external drive, using an app like SuperDuper or Carbon Copy Cloner. This enables you to access all your old files, and the drive can be re-cloned to the internal drive if you want to restore your Mac. Read more about this step here.
- Deauthorise your iTunes store account. (You should also deauthorise any third-party apps, such as Photoshop, that are locked to your Mac.) Read more about this step here.
- Sign out of and disable iCloud. Read more about this step here.
- Restart the Mac in Recovery Mode. Hold down Command and the R key during restart - or use alternative key combination as appropriate (We have a detailed tutorial on using Recovery Mode here).
- Use Disk Utility to erase the hard drive. Click on Disk Utility > Continue. Select the main volume and click Unmount then Erase). Quit Disk Utility (Disk Utility > Quit Disk Utility). Read more about this step here.
- Click on Reinstall macOS or Reinstall macOS and Continue. Follow the instructions to reinstall macOS. Read more about this step here.
The process of resetting a Mac or MacBook to factory settings gets rid of all your data stored on that machine. Obviously, before wiping your Mac you should copy the data from your old Mac to a new one. This can be done simply using Time Machine - we explain how to back up using Time Machine here and how to move your data to a new Mac using Time Machine here.
It's also worth making a clone of the whole hard drive and keeping it around for a while, just in case.
The best way to do this is using a program like Carbon Copy Cloner or SuperDuper (both are available as free trials) along with an external hard drive. Choose your main hard drive in the source, and your external hard drive in the Destination. Now click on Clone.
You should be able to boot from the cloned external hard drive. To test this, reset your Mac and hold down the Option/Alt key when you boot up your Mac. Use the arrow keys on your Mac to select the external drive and tap Enter. We have more information about running your Mac from an external drive here.
This cloned drive can be re-cloned back to the main drive if you decide to restore your Mac, or it can be used to access all the original files from your computer after you have wiped the internal hard drive.
You should deauthorise your computer from iTunes. This means it will no longer be linked to your iTunes account. You can only use up to five Macs to play music and movies that are locked to your iTunes account, so you shouldn't pass that on to another person.
The precise method of deauthorising iTunes varies depending on which version you've got. In the latest version (iTunes 12) you'll need to open iTunes and click Account > Authorisations > De-authorise This Computer. Enter your Apple ID and password and click De-authorise.
In older versions (below) you'll need to click Store > Deauthorise This Computer.
FileVault encrypts the files on your hard drive, and it's better to turn it off before going any further (you'll be wiping the files soon, so security shouldn't be a concern).
- To turn off FileVault, start by opening System Preferences.
- Click on Security & Privacy.
- Then select the FileVault tab.
- Check that it says 'FileVault is turned off for the disc [name of main hard drive]'. If not, click on the padlock icon in the bottom left, enter your user name and password and click on Unlock.
- Now click Turn Off FileVault.
- You will need to enter your user name and password again and you may need to wait a while while decryption takes place.
The next step is to turn off iCloud. Before you start, if you have any iCloud files that were created on that Mac they will be archived into your home folder (so remember to copy them to your backup).
- Open System Preferences and click on iCloud.
- Tap on Sign Out.
- To remove all your personal data, deselect each box beside: iCloud Drive, Contacts, Calenders and Reminders. Then click Continue. (Or click 'Delete From Mac' on each popup if you are using an earlier version of MacOS.
- You may see a warning that iCloud Drive needs to finish updating before continuing with sign out.
- If you have a MacBook Pro or MacBook Air with Touch ID you will need to confirm that your payment details should be removed from the Mac. Signing out will remove any Apple Pay information.
- Next you will be required to enter your Apple ID password.
Now you just need to wait while iCloud does its stuff.
Now you have backed everything up, and shut off your iCloud connections, you are ready to wipe the Mac.
- To enter Recovery Mode, click the Apple logo at the top left of the screen and select Restart.
- Imediately hold down the Command and R keys until you see an Apple logo or spinning globe. (You may be better off using a different key combination depending on the age of your Mac, and which macOS you want installed or was installed on the Mac when you bought it - we have a complete guide to starting a Mac in Recovery Mode here). For example, Apple recommends that "if you're selling or giving away a Mac that is using OS X El Capitan or earlier, use Option-Command-R to make sure that the installation isn't associated with your Apple ID". Read about the three different key combinations you can use to enter Recovery Mode, and the differences between them, here.
- Expect it to take a while for the Mac to start up in this mode.
- You may see a screen asking you to choose a language.
- The next screen you'll see is the Recovery Mode Utilities window. In Sierra, High Sierra and Mojave it looks something like this:
If you are having problems because Command R isn't working read this: How to reinstall MacOS if Recovery won't work.
Now you are ready to erase your drive...
- Select Disk Utility from the options, and click Continue.
- Click on your main hard drive (typically called Macintosh HD) in the sidebar on the left (you're looking for the disk name, not the volume name indented underneath it if that appears).
- To wipe your hard drive, click the Erase button then click Erase. Note that this permanently erases all data on the hard drive so don't do this unless you've cloned the drive or are happy to never access anything on that drive again.
- When it's finished, exit the program by going to the top menu and selecting Disk Utility > Quit Disk Utility.
You can't just sell your Mac having erased the contents, you now need to reinstall macOS.
You should still be in macOS Utilities.
- Select 'Reinstall macOS' or 'Reinstall OS X' from the option and click Continue.
- You will see a screen that indicates that your Mac will install the version of macOS your Mac shipped with. Click Continue.
- Now you need to agree to the terms and conditions before the software will install. Click Agree.
- Choose where you want to install the software - this will be the Macintosh HD shown. Click on that and then click on Install.
- Your Mac will download and install a fresh copy of macOS on the Mac, this may take some time.
- macOS will restart when installation is complete. You may be asked for your Apple ID and password.
If you're passing on the machine, it's wise to quit the setup assistant at an early point and allow the person buying the Mac to enter their own information.
How to install an older version of Mac OS X using Recovery mode
We have another article that goes into more detail on what to do if you want to install an older version of MacOS. But if you want to install an older version of the Mac operating system this is what to do:
If you are running Sierra 10.12.4 of later, pressing Shift + Option + Command + R when you first boot up your Mac into Recovery mode will allow you to install the version of MacOS that came with your Mac, or the one closest to it that is still available.
If you need to install an older version of the Mac operating system and are wondering how you can do that if you don't have the original discs, read this: How to install old Mac OS X versions.