If you have come this far, it is most likely because you want to install an old version of macOS or Mac OS X on your Mac. And that can be motivated by several reasons.
Maybe you are used to wearing a software And now you’ve found that it doesn’t work quite well with the latest version of macOS, so it would do you good to go back to an earlier version.
It may also be the case that you work as a developer and need access to multiple versions of macOS to be able to make sure that your software works fine on all.
Or, you just might not like the version of macOS you just installed and want to back out.
Whatever the reason you want to install a previous version of macOS, the truth is that it is possible to do so and in this article we will explain the steps you must follow.
In case you want to go to the previous version of the macOS that you currently have installed, you will be interested in reading our tutorial How to roll back from macOS Big Sur to Catalina or earlier versions.
How to install an old version of macOS on your Mac
Now, it’s time to see the steps to follow to install a previous version of macOS on your Mac: from checking if your Mac is compatible to downloading previous versions of macOS, going through the process to install them.
Step 1: Check if your Mac is compatible with that version of macOS
First, you will have to verify that your Mac can indeed run the version of macOS or Mac OS X that you want to install.
As a guide, your Mac will be compatible with the version of macOS or Mac OS X that it came with when it was released and any version that has arrived after its purchase (until Apple has decided to no longer support it).
That means there’s bad news: it’s highly unlikely that your Mac will be able to run a version of macOS or Mac OS X earlier than the one it had installed when you bought it.
You may not be able to install an older version of Mac OS X on a new Mac because the drivers for the hardware the new Max just didn’t exist when it was created in the software ancient.
What’s more, Macs cannot run an earlier version of OS X than the one installed when purchased, even if this version is installed on a virtual machine. The only solution is to get an older Mac that is compatible.
Now that doesn’t mean there are no exceptions. For example, if you bought a Mac in 2017 with the same specs as its predecessor (or the model was introduced a few years earlier), you may be able to run an earlier version of macOS.
You may be interested in checking which versions of Mac OS X and macOS are compatible with your Mac or MacBook. You can also use our tutorial on how to install macOS on an unsupported Mac.
Step 2: Download the version of macOS or Mac OS X you need
Next, you will need to download the installer for the version of Mac OS X or macOS you want to install.
The steps to follow may depend on the version in question, so we recommend you take a look at our article How to get older versions of macOS.
Step 3: Or find an old backup on Time Machine
If you have a Time Machine backup from before you updated your Mac with the latest version of macOS, you’ll need to follow the steps below to do so.
Of course, remember that you will lose all that data created after the update, so it may be a good idea to save it so you can access it later.
Step 4: Install the old version of macOS on your Mac
Once you’ve downloaded the installer, you might think it’s as easy as clicking it to get your Mac to update (or downgrade). Unfortunately, it is not that easy.
If you have a newer version of macOS installed on your Mac, you won’t be able to install an older version on top of it. You will need to completely reset your Mac before proceeding with the installation of the old version of macOS or Mac OS X.
Don’t you feel like doing it? You have several options. You could install the version you need on an external drive, or you could also run two or more versions of macOS at the same time.
There are several methods for installing an older version of the Mac operating system on your Mac. The best option for you will depend on several factors, such as whether you want to run more than one macOS at the same time.
How to downgrade macOS with Time Machine
If you have a Time Machine backup older than your currently installed version of macOS, then this might be a relatively easy process for you.
Here are the steps to recover a previous version of macOS from a Time Machine backup:
1. Start your Mac and immediately hold down the ‘Command + R’ keys.
2. Keep pressing the keys until you see the Apple logo or the beach ball spinning.
3. When you see the ‘Utilities’ window, choose ‘Recover from Time Machine backup’ and click ‘Continue’.
Four. Click ‘Continue’ again.
5. Choose a Time Machine backup before you installed the version of macOS you want to get rid of and click ‘Continue’.
Remember that if you recover an old backup, you will lose all the data added since you updated your Mac to the version of macOS that you now want to uninstall.
How to return to the operating system that was installed on your Mac
Now that we talk about the concept of ‘Recovery’, you may want to go back to the version of macOS that the Mac came with when you bought it.
It didn’t work for us, maybe because the internet connection wasn’t very good, but theoretically it should work!
With macOS Sierra 10.12.4, this feature was introduced in macOS ‘Recovery’, and it should reinstall the version of macOS you bought your Mac with. Or at the very least, so Apple says.
The company says that you should shut down your Mac and then, while restarting it, press ‘Shift + Option / Alt + Command + R’ at the same time. You will surely need to use both hands.
Note that if you have a Mac with M1, this process has changed. However, being such a new device, you will not be able to install any version of macOS prior to Big Sur.
These are the steps that Apple indicates:
1. Start your Mac and hit ‘Shift + Option / Alt + Command + R’.
2. Once you see the macOS ‘Utilities’ window, choose the ‘Reinstall macOS’ option.
3. Click on ‘Continue’ and follow the instructions on the screen.
Four. Select a boot disk and click ‘Install’.
5. Your Mac should restart once the installation is complete.
Important: This will erase your entire Mac, so make a copy of what you want to keep before going through this process.
How to install an old macOS from a bootable installer
This process is known as “clean install”, which we discuss in more detail in our article. How to do a clean install of macOS. In this case, you will reset your Mac and install the version of macOS you want from scratch.
1. Download the installer for the version of macOS you want to install from the Mac App Store. Again, visit our article How to get older versions of macOS to find out how.
2. Use the installation file to create a bootable installer on an external storage device. For more information visit How to create a bootable USB to install macOS.
3. Next, you will need to delete all the data on your Mac by restoring it to factory settings. To do so, restart your Mac in Recovery Mode and press the ‘Command + R’ keys at the same time when it boots up.
Four. Your Mac will open ‘Disk Utility’. Click on ‘Disk Utility’, followed by ‘Continue’.
5. Select the main volume and click ‘Unmount’, followed by ‘Delete’.
6. Close ‘Disk Utility’.
7. Now, click on ‘Reinstall macOS’ and hit ‘Continue’. Follow the instructions to reinstall macOS using the installer you just saved to your external drive.
How to run an old macOS on an external drive
Running a version of macOS on an external drive is a good option if you intend to continue using the version of macOS currently installed on your Mac.
It is possible to run a version of macOS or Mac OS X from an external storage device connected to your Mac. To know how to do it, we recommend that you read our article How to install macOS on an external hard drive.
Once you have installed macOS on an external disk, all you have to do is press the ‘Option / Alt’ key when starting your Mac and choose to boot from that disk.
The advantage of using this method is that you will not need to reset your Mac. The big drawback, on the other hand, is that the old version of macOS may run a bit slow (especially if it is a slow USB).
How to run macOS on a partition or volume
Another good option, if you don’t want to be limited to a single installed version of macOS, is to install the other version (or versions) on a partition or volume.
Whether it is a partition or a volume will depend on the version of macOS installed on your Mac. It is much easier to install a version of macOS on a volume, but only the most modern versions are supported.
It will help you to consult our article How to create a dual boot in macOS.
How to install an old Mac OS X in a virtual machine
Before explaining how to install a version of Mac OS X in a virtual machine, it is important to take a look at Apple’s terms and conditions of use.
Starting with Mac OS X 10.7, Mac operating system versions can only run in a virtual machine if the Mac in question uses the same version.
That means that installing a virtual machine with OS X 10.8 on a Mac with another version of OS X is a violation of the license agreement of software of 10.8.
The newest version of OS X that legally allows it to be run in a virtual machine from a Mac with different OS X is Snow Leopard (10.6).
In these cases, the solution is to run the server versions of the OS you need, as long as you have obtained the license of software from Apple. Despite that, both VMware Fusion and Parallels support both versions.
Another element to take into account is that Apple’s use agreement does allow Mac OS to run in two virtual machines on the same computer, but these virtual machines can only be used personally (unless you are registered as an Apple developer ).
You should also keep in mind that, as we have said before, Macs cannot use a version of OS X that is earlier than the one they had installed when they came on the market, even from a virtual machine. If you want to use an older version of OS X, you will need to get an older Mac.
There are several packages of software that make it possible to run multiple versions of Mac OS (or even Windows) on one Mac. Parallels, VMware Fusion and VirtualBox.
Don’t miss our article on software Virtualization for more information. You may also be interested in how to install Windows on a Mac.