How to test Mojave (10.14) – and how to revert to your previous version of MacOS

Yesterday Apple announced the next major version of MacOS, MacOS 10.14, called Mojave. If Apple does the same like the past years, it will most likely be released on Sep 25, 2018.

As always, Apple put some exciting new features and major benefits into the new version of MacOS. And like in the past years, Apple will most likely soon distribute first preview or beta versions of Mojave.

So who wouldn’t want to try it immediately?

And of course risk-free, without jeopardizing production if you have just one Mac. Would be a catastrophe to have switched to a new operating system and then finding out that crucial production software, like QuarkXPress, Photoshop or Affinity Designer, will not run on it or has major issues.

Sure, all vendors will make the newest versions of their software compatible with Mojave; however official support will typically only happen days or weeks after the official release of MacOS 10.14 by Apple.

What if you want or need to test Mojave before with your production software and need a way to revert if not yet satisfied.

Best Practice to test Mojave risk-free

And in any case, as always, have a backup (Time Machine) beforehand. As Murphy says “The only backup you’ll ever need is the one that you didn’t make.”

And – after having made the backup best with Time Machine – turn off your automatic backup while you clone to not interfere.

The idea is

  • First-hand experience, as experience form other users migth differ (they use different tools, different fonts, different hardware).
  • Test in real life, so not a test system but a real production. So it needs to be like your production computer.
  • However you need an easy and quick way to revert (so Time machien could be too time-consuming)

Here’s my suggestion that I have used successfully for years: Create a bootable clone.

  1. Buy an external hard disk large enough to hold your system disk (“Macintosh HD”)
  2. Connect it to your Mac.
  3. Use Disk Utility to format the external disk as “GUID Partition Table”.
  4. Download Carbon Copy Cloner ( It has a free trial for 30 days; however I strongly recommend purchasing it, as it can save you a lot of trouble and money.
  5. Using CCC clone your hard disk to the external disk. So source is “Macintosh HD” and target is “External Drive”. Clone it completely. Everything. Bootable.
    Note that CCC tells you what it will create before doing it. Read the manual if you are unsure.
  6. Reboot your Mac and hold the Option key pressed. Boot from the external hard disk. Note: This might take  longer than normal, as you are using a connection that is typically a bit slower than an internal hard disk. Test whether everything works as before (ignore the slight difference in speed), it’s important to check that this is a real clone. If everything has worked fine, that’s your 1:1 backup and it’s even bootable.
  7. Shut down your Mac. Unplug external hard disk. Restart.
  8. Now upgrade your Mac to the new MacOS Mojave.
  9. Test everything thoroughly. Test all the applications you use frequently, all goodies, see whether you like the UI, whether all your input and output devices work (scanners, printers etc.). You can even simulate production.
  10. If everything works fine, you are done and can enjoy the new MacOS. Ignore the rest of this list ;-)

And how to revert

  1. First make sure that you backup everything that you changed using the new MacOS, e.g. documents that you worked on. For example, save it to a USB stick.
  2. Now shutdown your Mac. Connect the external hard disk again.
  3. Start your Mac from the external hard disk (by holding the Option key and choosing the external drive).
  4. Use CCC (Carbon Copy Cloner) to duplicate the cloned drive back to your internal hard disk. Clone everything back from source “External Drive” to target “Macintosh HD”. That’s important, don’t clone it the other way around.
  5. Shut down your Mac. Remove external hard disk.
  6. Restart your Mac. Everything should be now exactly the same as it was before you upgraded your Mac. Test it to be sure.
  7. Remember to copy any files you saved on the USB stick to your drive and continue working. Make a mental note to try that in a few weeks again once the applications that haven’t worked correctly are updated to support Mavericks.

Let me know please if this worked for you.

Compatibility information

If you want to see which version of QuarkXPress supports which version of MacOS, please see here:

For other applications, like Affinity or Photoshop, please see also here: