How to Easily Downgrade MacOS Monterey to Big Sur (or Earlier) WITHOUT Data Loss - Ultimate Guide

How to Easily Downgrade MacOS Monterey to Big Sur (or Earlier) WITHOUT Data Loss - Ultimate Guide

If you updated to MacOS Monterey and it's simply not for you, then no problem! We have created an ultimate step-by-step guide to help you go back to Big Sur without losing your data!

When I made another guide showing you how to downgrade MacOS Catalina to Mojave, lots of you found it useful and I thought I will keep creating these guides so everyone can follow them!

MacOS Monterey brings you with some new features including Tab Groups on Safari, Universal Control and of course, the new Maps, as well as features borrowed from iOS 15, such as Focus Mode, FaceTime and Messages. In contrast to MacOS Big Sur which had some performance issues last year, who wants to downgrade to Big Sur anyways?

The sad news are, when a new Mac version releases, compatibility issues are very common among developers. If you are a developer, you most likely have ended up with a particular programming language version to not work properly on your system. This was much more prevalent with the release of MacOS Catalina. For the average Joe, some apps may not be fully compatible with Monterey and may not be any alternatives, and hence, will cause the apps to crash or quit unexpectedly.

Due to these reasons, downgrading to back to Big Sur, is an option to be considered and I am ready to take you to the step-by-step process on how to get back to Big Sur. Oh, and this guide will work if you have an M1 Mac too!

Can I downgrade?

In order to be eligible to downgrade, you must own an Apple machine which was released before mid 2021. As the time of writing this article, every Mac computer is eligible to downgrade back to MacOS Big Sur.

What tools do I need to downgrade?

  • Your MacOS Monterey Computer.
  • If you have a MacBook, it must be plugged in during the whole process, to prevent any potential battery death.
  • An External Hard Drive (preferably an SSD) with at least double your computers total storage size. For instance, if your Mac has a total storage capacity of 1TB, consider to have an SSD of 2TB or more. IF you don't have one, I recommend you to buy this. Sizes of up to 4TB are also available and it also comes with both USB-C and USB cables.
  • A USB stick of a least 16GB of storage. If you don't have one, I recommend you to buy this. Sizes of up to 512GB are also available to use the USB stick for other purposes.
  • Enough available space to install the Mac OS Big Sure installer. Having at least 10-15GB is recommended. If more needed, you will be notified by the OS.
  • Back Up with Time Machine. Regarding on how to backup your data, please refer to our video here.

Before you get started...

I strongly STRONGLY encourage you to backup all of your data with Time Machine before you proceed to ANY of the following steps. Downgrading to Big Sur will restore your Mac to its factory settings and at that point, you will need to use your Time Machine backup to restore the data in your computer. Please take the time to backup all your data by following the video below:

Disclaimer: If you have installed any apps (or updated) with Monterey, then some apps may not be compatible with MacOS Big Sur. Since both Big Sur and Monterey don't support 32bit apps, the chances of this from happening are small, but possible. For developers, compatibility issues with Xcode or any other IDE (Integrated Development Environment) may also arise.

1. Download the MacOS Big Sur Installer Utility

Before doing anything, we need to download the MacOS Big Sur Installer. This can be found in the App Store. However, I want to also emphasise that you can downgrade to any MacOS version, as long as, your Computer supports it. A MacOS shall not be installed if it was released before the computer was released, for example, as my Mac was released in June 2018 and it came with MacOS High Sierra, then High Sierra is the earliest version supported on my Mac. Anything before that wont be supported.

Below, I am listing the App Store links so you can download the MacOS to which you would like to downgrade.

Please keep in mind that the download will take some time depending on your internet connection.

For this purpose of this article, we are going to use the term "Big Sur" when referring to the MacOS which you're downgrading. However, if you are intending to downgrade to MacOS Catalina for example, then assume I mean MacOS Catalina instead of MacOS Big Sur. The same method will be used to downgrade to any of the above mentioned MacOSs.

2. Create the MacOS Big Sur (or earlier) Installer Drive

Once you have downloaded the MacOS version of your choice, connect your USB stick to your Mac to which we are going to use in order to create the MacOS Big Sur Installer Drive. Please, remember that this method will erase your USB stick, so if you have any data in your USB stick, please move all your files to another external storage. If you have space remaining on your External Hard drive which you used to backup your Mac, then create a separate folder and drag your files in there.

2.1 Firstly open Terminal from the Applications folder by going to Finder > Applications > Utilities and choose Terminal (or by typing "terminal" on spotlight search by pressing on the cmd + space bar keys from your keyboard).

On your Terminal window, type this command sudo /Applications/Install\ macOS\ --volume  (with a space after it). You Terminal window should look like this:

However, if you are downgrading to:

  • MacOS Catalina, then type this command instead: sudo /Applications/Install\ macOS\ --volume 
  • MacOS Mojave, then type this command: sudo /Applications/Install\ macOS\ --volume 
  • MacOs High Sierra, then type this command: sudo /Applications/Install\ macOS\ High\ --volume 

Then, drag and drop your USB stick from desktop into terminal.

Remember to drag and drop your USB stick and not any other Hard drive. Finally, the command is complete and you're ready to press enter.

After this, a warning will appear on Terminal saying that your USB stick will be erased and if you wish to continue to press on Y. Simply press on the "Y" key from your keyboard and then press enter.

This process will create the MacOS Big Sur Installer Drive which we are going to use for the next step to install MacOS Big Sur.

3. Restore your Mac with Recovery Mode

There are some noticeable differences here, depending on what Mac computer you're using. If you are using a Mac with the T2 chip, which is one of the following:

  • iMac Pro
  • Mac Pro (2019 or later)
  • Mac Mini (2018 or later)
  • MacBook Air (2018 or later)
  • MacBook Pro (2018 or later)

Then you will need to disable the Startup Protection Utility from the Recovery Mode before proceeding. Otherwise skip to step 4.5.

For this part, be sure to have your USB stick connected to your Mac Computer as we will use it to install MacOS Big Sur.

3.1 Now go and reboot your Mac, by clicking on the Apple logo from the top left, then Restart. You may need to re-open this article on your mobile phone to keep following along. As soon as you hear the startup sound, hold down the cmd + R keys from your keyboard:

This will enter your Mac into Recovery Mode. On recovery mode, you can do all sort of stuff, such as manage security, restore MacOS and restore your hard drive. However, now we need to disable Startup Protection Utility.

3.2 To do this, click on Utilities from the top menu bar, and choose Startup Security Utility.

A small window will open. Here press on Enter MacOS Password... and enter your password you use to login to your Mac once you turn it on and then press OK.

3.3 Now the window with the settings we are looking for is open. Here, make sure to do the following:

  • On Security Boot, choose the No Security option. This option allows your Mac computer to read any formatted device connected to your computer (including Linux or Windows formatted Installer Disk).
  • On Allowed Boot Media, choose the Allow booting from External or removable media option. This allows your Mac to boot from any external device connected to your computer regardless whether it's protested by the T2 chip or not.

3.4 After doing this, reboot your computer by clicking on the Apple logo from the top left, then Restart. As soon as you hear the startup sound, hold down the option (alt) key from your keyboard (left to the cmd key) and from the boot menu selection, choose Install MacOS Big Sur (your USB stick). This will boot into the Recovery Mode of Big Sur in your USB stick.

3.5 Now it's time to erase our main Hard Drive. From the Recovery Mode Menu, choose Disk Utility and then click Continue.

Then from the Volumes list on the top left, select Macintosh HD. It should be the top option. Then click on the Erase button which is the middle button from the top left buttons horizontal list.

Please note, that this is the last step to confirm you have done a Time Machine backup of your data as this process will erase all of your data. This will also erase all of your partitions, including your Windows 10 partition if you have one.

Once that done, click on Erase Volume Group and wait until the restoration process is done. Then press on ok, and quit Disk Utility.

For M1 Users

If you are using an M1 Mac, then you will see an Activate Mac window. For security reasons, you will have to activate your Mac by clicking on Exit & Recovery. You may need to enter your iCloud password before you continue.

Another thing to keep in mind if you own an M1 Mac, is that the Recovery Mode won't be downgraded to MacOS Big Sur, meaning that when you enter Recovery Mode, you will see the option to re-install MacOS Monterey and not MacOS Big Sur. However, this won't impact your system in any way as Monterey Recovery Mode can work just fine with Big Sur.

4. Install MacOS Big Sur

Once you have finished with the restoration process, you are ready to install MacOS Big Sur. To do this, you first need to make sure to connect your external hard drive where you made your Time Machine backup in order to restore the data during the installation process.

4.1 Now you should be on the main menu of Recovery Mode from your USB stick and you should see the option (second option) saying Install MacOS Big Sur. Select it and press on Continue.

Then press on continue again and agree with the terms. Then, the installer will ask you which drive you would like to install MacOS Big Sur on. You need to select your main hard drive, the one you have erased. DO NOT SELECT YOUR TIME MACHINE DISK!

Then click continue. Now the Installer is installing MacOS on your computer which will take some time to finish.

4.2 Once the process is over, your Mac will be rebooted to the Set Up screen for MacOS Big Sur. You will need to follow the steps just like as you did, when you bought your Mac.

4.3 Setup your country of Region, Wifi etc, until you reach the Migration Assistant page.

5. Restore your Time Machine Backup

This is the last part, were we have to simple restore our data from the Time Machine backup you did earlier. If your external hard drive isn't connected to you Mac yet, this is the perfect opportunity to connect it.

5.1 From the Migration Assistant screen, make sure the From a Mac, Time Machine backup or Startup disk option is selected and then click on Continue.

After this, you need to choose your Time Machine backup disk icon, press continue and then choose your backup folder. Once that's done, you have the option to select which data you would like to migrate. Make sure you have all options ticked so you will transfer all of your data. After this, the Installer will ask you to enter you login password and then press on continue.

This process will take some time to restore all of your data to your Mac, so feel free to grab a coffee until this process is done. Your Mac will reboot as soon as your data have been successfully restored.

5.2 Finally, the process is over and you may continue with the setup process if there's anything left before logging in to your Mac. If not, then you will be prompted to the Login Screen. Enter your password and you may finally use your Mac with MacOS Big Sur!

6. Finalle!

Now you have installed a fresh copy of MacOS Big Sur, it's a good time to check if your apps are fully working as well as to check for any potential incompatibilities. If yes, you might benefit from downloading a previous version of that app. If you are a developer and there are some tools from your Development Environment which don't work, you may need to downgrade them to an earlier working version. Usually some Forums or Git will have some specific instructions on how to downgrade your tools or maybe to re-install them without losing any progress data.

Final Thoughts.

Phew! That was a long one and you certainly deserve to have a break after solving this difficult problem. If you managed to get back to Big Sur, why not take the moment to stay connected by subscribing to our mailing list at the very bottom of the page? By subscribing, you will be up to date with what are we up to and our latest recommendations. While it took me a good long 4 hour period to produce this high quality guidance for you, you can take a few seconds to support us by sharing this article to your friends and subscribing to ourYouTube channel! We tend to post high quality technical solutions, as well as product reviews and more.


I enjoy creating these long and detailed guides to ensure anyone can follow them of any technical levels, as you ending up with your problem solved. If you have any feedback which I could consider to make these articles better, why not take the time to let me know! I am always open to new ideas and new ways on how to make better guides and better articles overall!

I hope you stay safe and healthy!

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About the Author

George K.

Admin of TechLunar





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