Mac updates its macOS (previously Mac OS X) desktop and laptop operating system once a year, like clockwork, bringing new features and improvements. That's all very well, but the latest version of MacOS, known as Catalina, won't run on any Mac older than 2012, and in the case of the Mac Pro, late 2013. Which may well mean that your Mac can't be updated, unless you follow this tutorial.

Before you go ahead and follow the advice below, a word of warning. There is a reason why Apple chooses not to support the new Mac operating system on older Macs. Older Macs just don't have the necessary components or power required to cope with the demands of the more modern systems. So if you do install Catalina, or any recent version of macOS on an old Mac, be it Mojave, High Sierra, Sierra or something else, don't expect it to run smoothly.

Is my Mac too old to update?

Hoping to update your Mac with the latest version of macOS? Officially it might be too old to run the updated software.

Apple advises that macOS Catalina will run on the following Macs:

  • MacBook models from early 2015 or later
  • MacBook Air models from mid-2012 or later
  • MacBook Pro models from mid-2012 or later
  • Mac mini models from late 2012 or later
  • iMac models from late 2012 or later
  • iMac Pro (all models)
  • Mac Pro models from late 2013

Apple advises that macOS Mojave will run on the following Macs:

  • Mac models from 2012 or later
  • iMac Pro (from 2017)
  • MacBook models from 2015 or later
  • MacBook Pro models from 2012 or later
  • MacBook Air models from 2012 or later
  • Mac mini models from 2012 or later
  • Mac Pro models from late 2013 (plus mid-2010 and mid-2012 models with recommended Metal-capable GPU)

This means that if your Mac is older than 2012 it won't officially be able to run Catalina or Mojave. In the case of Catalina that includes all the old-style Mac Pro models, pre-'trash can'. 

macOS High Sierra had a little more scope. Apple said that would  run happily on a late 2009 or later MacBook or iMac, or a 2010 or later MacBook Air, MacBook Pro, Mac mini or Mac Pro.

We have a macOS compatibility checker here, so you can see which versions of macOS your Mac should be able to run.

However, despite this it is possible to run newer macOS versions on older Macs thanks to a patcher created by a developer. Although you should expect to encounter problems. This hack doesn't work with every Mac, but many are covered. You can see if your Mac is supported here.

Running Catalina on an unsupported Mac may also be considered against Apple's terms and conditions. For information about Apple's terms and conditions read: Should you agree to Apple's terms and conditions

How to run Catalina on an older Mac

The problem is that if you've got an older Mac then the Mac App Store simply won't let you install the upgrade file. But all is not lost. You can download a macOS Catalina Patcher from a developer known as DOSDude1. The patch will enable you to install Catalina on an older Mac.

DODDude1 offers a video tutorial on his website, here. We've simplified the steps below, but we recommend that you follow his tutorial.

  1. Download the latest version of the Catalina patch here. (You can make a donation).
  2. Open the Catalina Patcher app.
  3. Click Continue.
  4. Choose Download a Copy.
  5. The download (of Catalina) will start - since it's almost 8GB it is likely to take a while.
  6. Plug in a flash drive.
  7. Choose 'Create a bootable installer' from the options.
  8. Plug the bootable installer into the Mac you wish to update.
  9. Restart the Mac while holding the Option/Alt key. This will cause the Mac open in Startup Manager.
  10. Choose the bootable installer drive and Enter.
  11. Now your Mac should open in Recovery.
  12. Choose Reinstall macOS and wait for the new version of macOS to install.
  13. After the installation has completed, you should restart the Mac in Recovery mode again, choosing the drive that contains the bootable installer.
  14. Now choose macOS Post Install and the required patches will be installed on your Mac so that Catalina can work.
  15. When the patches have been applied choose Force Cache Rebuild.
  16. Restart.
  17. When it reboots, your Mac should now boot into a fully working copy of macOS Catalina.

If you are running a version of macOS that predates High Sierra or Mojave, you will need to format your hard drive to APFS.

We have more advice about installing macOS via a Bootable Installer here.

How to run Mojave on an older Mac

As with Catalina, a patch tool was written DOSDude1 that enables you to install macOS Mojave on an older Mac. 

You can download the Mojave Patch Tool here.

How to run High Sierra and older on an older Mac

DOSDude1 wrote a similar patch for High Sierra and prior to that Sierra. With the patch installed you can go back as far as early 2008 models. It's unlikely to run like a dream, which is why Apple advises against this course of action. But you should be able to achieve tolerable performance.

Why you shouldn't install MacOS Catalina on an old Mac

We'd advise tech beginners against attempting this workaround: it calls for a moderate degree of tech expertise.

Remember that we're going against Apple's official advice on this one, which means that if something goes wrong - and that's always a possibility with an OS install, even if you're using official software - your warranty is unlikely to save you. Of course, it's unlikely that your 2008 Mac would be under any warranty so that may not worry you too much.

Back up your Mac before going any further. And bear in mind two more caveats.

At some point Apple may patch this hack and prevent it working in future. So if you're keen, and happy that the risks and difficulties are worth it for you, then jump in while you still can.

Otherwise, you might want to read How to sell an old Mac.