Apple 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 recent versions of MacOS - such as Catalina and the soon to launch Big Sur - won't run on any Mac older than 2012 - in fact in the case of Big Sur that's 2013, and in some cases 2014. 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 Big Sur, 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?

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

Here's an overview of the Macs that will run Big Sur, according to Apple:

  • MacBook models from early 2015 or later
  • MacBook Air models from 2013 or later
  • MacBook Pro models from 2013 or later
  • Mac mini models from 2014 or later
  • iMac models from 2014 or later
  • iMac Pro (all models)
  • Mac Pro models from 2013 or later

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)

The older 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.

If you Mac is supported read: How to update to Big Sur from Catalina.

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'. If you want to run Big Sur, but your Mac is older than 2013/2014, the new macOS just isn't for you, as far as Apple is concerned anyway.

However, despite this it is possible to run newer macOS versions on older Macs thanks to a patcher.

Don't expect things to be plain sailing though - in fact you should expect to encounter problems. Be prepared for the fact that your Mac will not function optimally and you could lose data. (For that reason we recommend doing a full backup of your Mac first).

For example, many older Macs have problems with the Wi-Fi connection after installing macOS Big Sur. If you need Wi-Fi, installing the preview version is not advisable.

Running Catalina or Big Sur 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.

Wondering if it's worth updating your Mac? Read: macOS Big Sur vs Catalina.

How to run Big Sur on an older Mac

Big Sur will be arriving later this year - you can install a beta version right now if you want to (here's how to get the beta). However, if your Mac is more than a few years old and you try to install Big Sur on it you will hit a few hurdles - the first being the fact that Software Update simply won't let you install the new version of macOS.

However, this doesn't mean that installing Big Sur on an older Mac isn't possible. It is - you just need a patch. Luckily there's already a patcher for installing macOS Big Sur on older Macs available on GitHub.

Note that macOS patchers cannot perform magic and not all Macs will be compatible. Before installing Big Sur on an older Mac, make sure that your Mac is compatible with the patcher. On the patch page you will find some notes indicating the various years of manufacture. Before you upgrade to macOS Big Sur, review this.

The procedure for updating to a new version of macOS on incompatible Macs is as follows:

  1. First you will need to obtain the installation files for the operating system and load these installation files onto a USB stick and prepare the USB stick for installing macOS Big Sur. We explain how to create a bootable installer of macOS on an external drive here. (You'll have to obtain these using a compatible Mac).
  2. Next you need to obtain software that is able to trick the installation files of the version of macOS you want to install into believing that the Mac is compatible. You can download the patcher from GitHub here. Click on the Code and Download Zip buttons.
  3. After extracting the archive from your download you will find the file "micropatcher.sh".
  4. Open a terminal window and drag and drop the file into the terminal. Then run the command.
  5. Now install macOS from your bootable installer.
  6. In some cases, there are still tasks to be performed after the installation. These can be found in the instructions for big-sur-micropatcher. After preparing the Mac with the USB stick, start a terminal and enter "/ Volumes / Image \ Volume / set-vars.sh". The script is part of the patch for macOS Big Sur and changes important settings for booting and system files.

Install Big Sure old Mac

As soon as you have installed a beta version of macOS Big Sur, updates will appear in macOS as soon as they are available. However, you should not install these, but ideally again create a USB stick with the current installation files and install the update in this way.

The update can take several hours. In our case it sometimes looked like the installer had crashed during the update. In this case you should wait, as the installation is usually still in progress. Over time, better ways to update a machine may be found. Currently, the safest approach is to update using a bootable USB stick.

These steps were translated from an article by our colleagues at Macwelt.

How to run Catalina on an older Mac

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.

The Catalina hack doesn't work with every Mac, but many are covered. You can see if your Mac is supported here.

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 new macOS 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.

We've had a look at what's coming in Big Sur - here's our verdict: macOS Big Sur: should you update your Mac?