How to Dual Boot Two macOS on Mac?

It is quite common when users hear about the release of the new macOS and wants to try it. However; it is not quite the right idea for just checking, they should do the entire installation on their Mac.

macOS in beta or early versions can have numerous errors or issues which can push users to downgrade to either earlier version of macOS. Instead of upgrading or downgrading, you can dual boot two macOS on your Mac and if didn’t like then you can uninstall any of the macOS.

Here we have dual-booted macOS Monterey and macOS Big Sur. However; the method is not limited to these two macOS. As you can use the exact same method to perform dual boot two macOS on any Mac.

Why to Dual Boot two macOS?

Here are some of the reasons why you shouldn’t upgrade your macOS and instead do dual booting.

• Like we mentioned before, new macOS has tons of issues that includes screen freeze, application compatibility error and more. There are also security risks with macOS beta versions.
• There are applications that are either fully updated and won’t work with earlier versions of macOS or you want to use an application from the past and now the newer version of macOS has compatibility error.
• You can also toggle between two macOS on a single system.

Related: Easy way to Dual Boot Windows 11 and Windows 7

Prerequisite for Dual Boot macOS

Before we begin the dual booting process, let’s make sure you have any of the Apple products below:

iMac Pro 2017 or later

iMac 2012 or later

Mac Pro 2013 or later

MacBook 2015 or later

MacBook Pro 2012 or later

Mac Book Air 2012 or later

Don’t forget to have a backup of your files. Even though the procedure is easy, still having a backup can be quite handy in case of data loss.

NOTE: if you are planning to use earlier versions of macOS, then you will need to check the system requirement and then perform the installation.

Related: How to Dual Boot Ubuntu & Windows 10?

Dual Booting two macOS

By now I am quite sure that you have macOS Big Sur on your Mac. If you are having other versions of macOS then it is OK. There is no specific need for any macOS, you will just need an installed macOS on your Mac. Then you will perform the procedure given below, step by step.

1: Create a new Disk

We will begin the procedure by creating a new disk or volume on your Mac. We will make sure, the new macOS is having APFS (Apple File System) which is required for macOS Monterey. Earlier versions of macOS supported HFS+, newer versions require APFS. HFS+ is replaced with APFS for improved performance, stability, and security.

NOTE: it is recommended to have an extra/external drive for your new macOS installation. As files and folders will increase by number and size on your disk which can cause slow performance.

Here you go to Disk Utility which can be opened with Command+Space keys or by typing “diskutlity” in Spotlight.

Inside the Disk Utility, you will click the View button which is a drop-down menu. Now click on Show All Devices and select your home volume.

NOTE: if you are having any external drive on your Mac then you will select the external drive instead of the home disk.

Click on the + button. Now give Name and change the Format of your new volume (which should be APFS+) and click on Add.

If you want to change the size of your new volume, then you will click on Size Options which gives the volume the Name, and change the Format.

2: Download the new macOS for dual boot

Here you are going to download the macOS Monterey (which we are using here). It is totally up to you, which macOS you are going to download.

If you are going to use any beta version of macOS then you will access the Apple Beta Software Program with your Apple ID on the Apple website. There you will download the beta version of macOS.

Else for downloading macOS, then you will visit the Apple website and download the installer. Before you continue to the next step, you will use the installer for downloading the full macOS.

Related: Free Download macOS 12

3: Installation of new macOS

You will go to the macOS downloaded and will double click on it. The installation will take place. Here you are going to install macOS like any other macOS. The only catch will be to select the newly created volume/disk for installation. From basic to advanced, you will complete the installation.

During the installation, if needed you will also format the newly created volume/disk. Then will continue the installation of macOS. Once the installation got completed then you will restart your Mac.

4: Toggle between the two macOS installed on your Mac as dual boot

After the installation of the macOS on your Mac then you will restart your Mac. While your system starts, you will press ALT/OPTION keys and soon a prompt will appear on your screen. Here you are going to select between the two macOS.

For changing again, you will restart your Mac again. Press the ALT/OPTION keys and in the prompt select the macOS.

Related: How to Dual Boot macOS Big Sur and Windows 10 on PC?
Related: Install Windows 10 on macOS Big Sur using Boot Camp