How to Install Older Versions of macOS or OS X on A Computer?

For personal or professional reasons, you may need to install an older version of macOS and Mac OS X on your computer. Indeed, this may be necessary in certain situations.   For example, if you need to test an application or a website on an older system. Or you may simply not like the new macOS update.

If you want to switch back to an older operating system, there are several options.

Is your Mac compatible?

Before getting down to business, it’s important to make sure your Mac is compatible. As a guide, your computer should be able to run any supported version of macOS or Mac OS X when it is launched, as well as any updates released in the years following your purchase.

Check If Your Mac can Run An Older macOS Version

Before you can reinstall a previous macOS version on your computer, you must first determine if your Mac will be able to run it.

If you have a newer model, then the hardware drivers may not be compatible with the older software. In this case, they will have great difficulty working, even with a virtual machine.   Similarly, if you were hoping to put the latest macOS system on an older Mac, you won’t be able to.

Be aware that there may be exceptions, for example, if you bought a Mac in 2017 and its specifications are no different from its predecessor. To help you find the macOS versions supported by your Mac, refer to these lists:

macOS Monterey :

MacBook (2016) or later
MacBook Air (2015) or later
MacBook Pro (2015) or later
Mac mini (2014) or later
iMac (2015) or later
iMac Pro (2017) or later
Mac Pro (2013) and later
macOS Big On :

MacBook (2015) or later
MacBook Air (2013) or later
MacBook Pro (2013) or later
Mac mini (2014) or later
iMac (2014) or later
iMac Pro (all models)
Mac Pro (2013) (2019)
macOS Catalina :

MacBook (2015 to 2017)
MacBook Air (2012 to 2019)
MacBook Pro (2012 to 2019)
Mac mini (2012 to late 2018)
iMac (2012 to 2019)
iMac Pro (all models)
Mac Pro models (2013)
macOS Mojave :

MacBook (2015 to 2017)
MacBook Air (2012 to 2017)
MacBook Pro (2012 to 2018)
Mac mini (late 2012 to late 2018)
iMac (late 2012 to mid-2017)
iMac Pro (all models)
macOS High Sierra :

MacBook (2009 to 2017)
MacBook Air (2010 to 2017, same as 2015 model)
MacBook Pro (2010 to 2017)
Mac mini (2010 to 2014)
iMac (2009 to 2017)
Mac Pro (2010 and 2013)

Download the version of macOS, or Mac OS X, of Your Choice

If your Mac is ready for an older operating system, then it’s time to download the right installer.

  • Download macOS Mojave
    Although Mojave updates are done via Software Updates, you can download the installers from the Mac App Store, even if you’re on Catalina.  You can get macOS Mojave via this Mac App Store link, follow the instructions and click Get.

The software update will open the Search for Update window, and then you will be asked to confirm the download.  This is not an update per se, but the full Mojave installer.  Once downloaded, do not click Install or the program will be automatically deleted. It should be in your Applications folder.

  • Download macOS High Sierra
    You can download High Sierra via the Mac App Store, however,  you cannot download High Sierra if your macOS is running Catalina. If this is your case, then use a Mac running an older version, then log into the Mac App Store with your password and download High Sierra, do not install it. It will be placed in your Applications folder.


You can also find updates to the older version of macOS on this Apple page, but these are point updates and not the full version.

  • Download macOS Sierra
    You’re allowed to download Sierra via Mac App Store.  In 2017, when Apple released macOS High Sierra, the company removed Sierra from the list of products purchased. This made it more difficult to return to this version, but it is still possible to download Sierra.


Note that if you are using Mojave, then an error message will inform you that it is unable to find the update. So you will need a macOS that is not running Mojave.


  • Find an old Time Machine backup

If you have a Time Machine backup from before you updated your Mac, you can go straight to this step, which we have described below.  However, note that you will not recover any data added from this one.


 Install An Older Version of macOS on Mac

Once you have downloaded the installer, running it is not as easy as you might think. If your Mac has a recent version of macOS then you won’t be able to recover an older version without completely erasing the contents of your computer. The advice beforehand would then be to back up everything to an external drive. Otherwise, the most appropriate installation method will depend on a number of factors.

1- Revert to an older macOS version using Time Machine
If you are using Time Machine to back up your Mac, then you can revert to a previous version of macOS by following the steps below:
Start your Mac by holding down Cmd + R until the Apple logo appears.
When you see the Utilities window, choose Restore from Time Machine Backup, click Continue.
Click Continue again.
Choose your Time Machine backup, finish with Continue.
Remember that when you recover an old backup, you will lose the data added since the last update of your Mac

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