There are a few reasons why you might want to install an one-time version of macOS or Mac OS Ten:

Mayhap you are relying on software you lot take discovered doesn't work properly in the newest version of macOS and you lot want to downgrade macOS.

Maybe you lot are a developer and you demand to be running multiple versions of macOS so that y'all tin can be sure that your software runs correctly on them.

Or maybe you simply don't like the version of macOS that you have installed.

Whatever your reason for wanting to install an older version of macOS the great news is you can install an older version of macOS and nosotros will explain how.

If you lot want to downgrade the latest version of the Mac operating system to the one earlier then you might observe information technology helpful to read: How to downgrade macOS Monterey to Big Sur or older.

Install older macOS

We'll walk you through all the steps below for installing an older version of macOS on your Mac - from making certain your Mac can run the version, to where to download the old version of macOS from, and how to install the old version on your Mac. We'll besides explore some of the issues you might see along the way.

Step 1: Cheque your Mac can run the macOS version

First y'all need to confirm that your Mac will be able to run the version of macOS or Mac Os Ten you desire to install.

As a guide, expect your Mac to be able to run whatever version of macOS or Mac OS 10 that was supported when that Mac launched, and whatever that were released in the few years immediately post-obit your purchase.

Now for the bad news: Information technology is unlikely that your Mac will be able to run a version of macOS or Mac Os Ten that is older than the ane that was installed on information technology when yous bought it. You may find you can't install an old version of Mac OS X on a new Mac because the drivers for the hardware in your new Mac simply don't be in the old software, and then it can't run.

Simply speaking, Macs cannot boot into an Os X version older than the one they shipped with when new, fifty-fifty if it's installed in a virtual machine. If you want to run older versions of Os X on your Mac, you demand to become an older Mac that can run them.

Still there may be exceptions, for instance, if yous bought a Mac in 2017, only the spec hadn't inverse from the predecessor, or the model was actually introduced a few years earlier, you may find you can run an older version of macOS on information technology.

To help yous detect out what versions of macOS your Mac supports we take a full list of which Macs each version of Mac Os X and macOS.

If you are installing an former version of Mac OS X on an one-time Mac you shouldn't accept likewise many difficulties though.

Similarly, if you were hoping to install newer version of macOS on an old Mac yous might notice that you lot can't. This is because newer versions of macOS tend to drop support for older Macs. We have a dissever article most installing macOS on an older Mac.

Install old macOS

Step 2: Download the version of macOS, Mac OS X y'all require

Adjacent you need to download the installer for the version of Mac OS X or macOS you wish to install.

We take a separate article almost how to download an onetime version of macOS or Mac OS 10, and so if you haven't got the version of the Mac operating system you desire pop over there for advice on how to get it...

Step 3: Or notice an old Time Automobile backup

If y'all have a Time Auto backup from before you updated your Mac to a newer macOS you can bound to this section. Merely remember you won't be recovering any data y'all have added since you lot upgraded so you might want to save that somewhere you volition be able to access later on.

Step 4: Install the older version of macOS on your Mac

Downgrade macOS

In one case you have the installer downloaded you might recollect y'all can just click to install information technology and your Mac volition be updated (or rather, downgraded) with the older version. Unfortunately information technology's not that simple.

If your Mac is running a newer version of the macOS you won't be able to install an older version on tiptop of information technology. You will take to completely wipe your Mac before you can install an older version of macOS or Mac Os X.

Non keen on completely wiping your Mac? There are options. You could install the version you require on an external drive, or yous could run two or more versions of macOS alongside each other.

There are really multiple methods you can apply to install an older version of the Mac operating system on your Mac. The most appropriate method for you will depend on a number of factors including whether y'all desire to run more than than ane version of macOS.

Below we will look at the following options:

  • Recover from a Time Machine backup
  • Revert to the version of macOS installed when yous purchased your Mac
  • Install macOS using a bootable installer
  • Run the version of macOS on an external drive
  • Run the version of macOS in a sectionalization or a book
  • Run the version of macOS in a virtual machine

We as well have dedicated manufactures for these unlike methods that go into more item, yous'll observe links below.

How to revert to an erstwhile macOS using Time Machine

If yous accept a Time Machine fill-in that predates the version of macOS that you want to bid farewell to, and then this could be the simplest solution for you.

Here are the steps you need to take to recover an older macOS from a Time Machine backup:

  1. Start up your Mac and immediately hold down Command + R.
  2. Continue belongings both keys until you see the Apple logo or a spinning globe.
  3. When y'all run into the Utilities window choose Restore from Time Machine Fill-in and click on Continue.
  4. Click Proceed again.
  5. Choose a Time Machine fill-in from before you lot installed the version of macOS you wish to revert from and click on Continue.

Think that if you recover from an one-time fill-in yous will lose the data y'all take added since updating to the version of macOS you wish to uninstall.

Here's how to restore your Mac from a Fourth dimension Motorcar fill-in.

How to downgrade to the OS that shipped on your Mac

While we are talking about Recovery, you lot might like to try the following method of downgrading your Mac to the version of macOS information technology shipped with. (It didn't actually work for us when we tried, peradventure because our internet connection wasn't good plenty, but it should work in theory!)

This has been a feature in macOS Recovery since macOS Sierra 10.12.iv, and it should reinstall whatsoever version of the macOS your Mac shipped with, co-ordinate to Apple.

Apple explains that you lot should shut down your Mac and so as you restart press Shift-Option/Alt-Command-R together (this is not like shooting fish in a barrel one-handed!).

Note that if you accept an M1 Mac the procedure for starting in recovery mode has changed - read all the new ways of doing things on M1 Macs - however, you won't be able to install any macOS older than Big Sur.

Hither are the steps Apple describes:

  1. Offset up your Mac pressing Shift-Pick/Alt-Control-R.
  2. In one case you see the macOS Utilities screen cull the Reinstall macOS option.Recovery Mode Mac
  3. Click Continue and follow the on-screen instructions.
  4. Select your startup disk and click Install.
  5. Your Mac volition restart once the installation is complete.

Notation: This will wipe your Mac so make a copy of annihilation you want to keep!

How to install an old macOS using bootable installer

This is a process known as a make clean install, which we look at in more detail hither: How to practice a clean install of macOS. You will be wiping your Mac and installing the version of macOS you require on a make clean slate.

  1. Download the installer of the version of macOS that you require from the Mac App Shop. Follow the instructions here.
  2. Employ this installation file to create a bootable installer on an external storage device. Read almost creating a bootable installer here.
  3. Next yous need to completely erase everything from your Mac, restoring it to factory settings. To start this process, restart the Mac in Recovery Mode past property down Command and the R central during restart.
  4. Your Mac will open in Disk Utility. Click on Disk Utility > Continue.
  5. Select the principal volume and click Unmount so Erase.
  6. Quit Disk Utility (Disk Utility > Quit Disk Utility).
  7. Now click on Reinstall macOS or Reinstall macOS and Continue. Follow the instructions to reinstall macOS using the installer yous merely saved to the external drive (link to separate article above).

Installer Mojave

How to run an older macOS on an external bulldoze

Running a version of macOS on an external drive is a not bad solution if yous wish to continue to run the version of macOS currently installed on your Mac.

It is possible to run a version of macOS or Mac Os X on an external storage device plugged into your Mac.

Rather than go through the steps here, we'll direct you to this article about how to run How to run macOS on an external bulldoze.

Once you have installed macOS on the external drive all you demand to practice is concur Option/Alt down when you start upward your Mac yous tin can choose to boot from that drive.

The benefit of this method is you don't need to wipe your Mac. The disadvantage is that the older version of macOS might run slowly - especially if it's on a dull USB memory stick.

bootable drive

How to run an macOS in a partition or volume

Some other neat choice, if you don't desire to be limited to running but one version of macOS is to install the other version (or versions) on a partition or volume.

Whether information technology's a sectionalisation or volume depends on the version of macOS that is primarily installed on your Mac. It's a lot easier to install a version of macOS on a Volume, just merely newer versions of macOS support volumes.

We look separately at how to run two versions of Mac Os X on separate partitions/volumes.

Install macOS partition

How to install an older Mac OS X in a virtual machine

Before we look at how to install a version of Mac OS Ten on a virtual machine we need to look at Apple'southward finish user license agreement. This is a legal minefield. Read most Apple's Terms and Conditions and the EULA here.

Since Mac OS X 10.seven versions of the Mac operating organisation are only licensed to be run in a virtual machine if the host Mac is running the same version. This means that installing an OS Ten 10.viii VM on a Mac running another version of OS Ten is a violation of the 10.viii software license understanding. The newest version of OS 10 that tin can legally exist run in a virtual motorcar with a different OS X host is Snow Leopard (10.6).

The solution hither is also run the server versions of the Bone that you crave, as long as you have the software license from Apple.

Despite this, VMware Fusion and Parallels do back up Bone X customer equally well equally server versions.

Another thing to annotation is that Apple's cease user agreement does allow yous to run the Mac Os on two virtual machines on 1 computer, only these virtual machines cannot be used for business (unless you're a registered Apple developer).

Also behave in heed, as we mentioned before, Macs cannot kicking into an Os X version older than the one they shipped with when new, fifty-fifty if it'due south on a virtual machine. If y'all want to run older versions of Bone X on your Mac, you demand to get an older Mac that can run them.

In that location are a number of software packages that make it possible to run multiple versions of the Mac Bone (and even Windows) on your Mac. These include Parallels, VMware Fusion, Virtual Box. Find out which is best by reading: Parallels, VMware, VirtualBox compared.

Related to virtual machines, you tin likewise run Windows and employ Windows apps the same way, read: How to run Windows apps on a Mac and How to install Windows on a Mac.