Apple's strategy of making macOS updates available for free from the Mac App Store and providing access to public betas of upcoming new versions has been very successful in encouraging us to keep our Macs updated. However, sometimes enthusiasm for the newest features can get the better of us and we upgrade in haste only to repent later.

Perhaps bugs in the public beta broke an app you depend on, or maybe features you relied on work differently or have disappeared in a newer version of macOS. Maybe software you rely on no longer works - if you were using Microsoft Office 2011 for example you may find that the apps you rely on no longer work. 

Whatever your reason for hating the new MacOS, you may be wondering if you can revert back to the older version of the operating system.

Unfortunately downgrading to an older version of Mac OS X isn’t as simple as finding the older version of OS X and reinstalling it. Once your Mac is running a newer version it won’t allow you to downgrade it that way. But it is still possible to downgrade your Mac.

In this article we show you how to downgrade macOS.

How to revert from MacOS Sierra, or High Sierra to an older version

The good news is that if you are trying to revert from Sierra to the version of Mac OS X that shipped on your Mac it should actually be an easy process, thanks to a new feature in Recovery mode in version as of MacOS since Sierra 10.12.4.

Apple explains that you should shut down your Mac and then as you restart press shift-Option/Alt-Command-R all together (this is not easy one handed!).

This command will reinstall whatever version of the macOS your Mac shipped with, according to Apple. Unfortunately when we tried it the process didn’t work, we got stuck in a loop where we kept seeing a warning that our right to download the software would be verified with Apple, but each time we clicked Continue on that window, and then Continue on the installation window, we’d return to the verification window. Apparently to verify eligibility your Mac serial number is sent to Apple and your Apple ID may be required, it’s not clear why this wasn’t working for us.

This was made all, the more frustrating by the fact that it had already taken an hour for the Mac to start up in this mode, with a globe rotating and a time indicator which kept flicking between 0:26 and 3:14.

This process may work for you however, so on that assumption, here are Apple’s instructions:

  1. Start up your Mac pressing shift-Option/Alt-Command-R.
  2. Once you see the macOS Utilities screen choose the Reinstall macOS (or Reinstall OS X) option.
  3. Click Continue and follow the on screen instructions.
  4. Select your startup disk and click Install.
  5. Your Mac will restart once the installation is complete.

While this process didn’t work for us, that may be due to the fact that we were running a beta version of High Sierra, perhaps once the software is out of beta the process will work properly.

How to remove a macOS beta

The guide below should work for both beta and full release versions of macOS or Mac OS X.

However, don’t count on the fact that you will easily be able to remove the beta. When deciding to install a beta it is doubly important that you back up of your system first because so many more things can go wrong.

In fact, we would advise that when you install a beta version of a new macOS upgrade, you install it on a separate hard drive. You can find out how to do that here: How to run macOS from an external hard drive.

That way you can test the beta while keeping your files and data safe from any bugs.

Nevertheless, if you've already installed a beta on top of your existing system, the process for reversing it is exactly the same as for a full version. Follow the instructions below to wipe your startup disk and re-install the latest full version of macOS.

Restore an old MacOS from a Time Machine backup

As with anything else, the key to minimising difficulty later is to prepare before you start.

The simplest way to reverse an OS update is to restore from a Time Machine backup. If you prefer to use an alternative to Time Machine such as the free Carbon Copy Cloner, you should still be able to revert to the older version of the OS using our guide.

All you need is a recent, complete backup of your system from before the upgrade. That backup can be on a directly connected external disk, hooked up by USB, FireWire or Thunderbolt. Or it can be on a Time Machine compatible network drive, like Apple's Time Capsule.

If you're running macOS Sierra or High Sierra, the network drive can use the SMB protocol; note that older versions of macOS only support AFP for Time Machine backups.

If you've got a Time Machine backup that you can use to revert to an older version of the OS, read this section. If not, skip ahead to Downgrade without a Time Machine backup below.

Before we begin, it's important to note that when you restore from a backup, you'll wipe everything on your startup disk. That means any work you've done since you upgraded will be lost. So… back it up. You can use Time Machine to do this, too. If you don't use Time Machine, clone your startup disk to a spare external drive or at the very least make a copy of any files you've created or modified since you upgraded. If you've got photos in the Photos app and you don't use iCloud Library, manually export them to an external disk so you can re-import them later.

  1. Once you've backed up everything you want to keep from the newer version of the OS, restart your Mac with the Time Machine disk connected and while holding Command and R until you see the Apple logo.
  2. When the options appear on screen, choose 'Restore From Time Machine Backup' and click Continue.
  3. The next screen will show the words Restore from Time Machine, click Continue again.
  4. Next select your Restore Source - your backup drive.
  5. The next screen shows all your backups over time, pick the last one you made prior to updating to the newer version of the Mac operating system. (You can tell which version of macOS the back up was made in).

Now that you have restored the older version of macOS or Mac OS X you can recover the files you created in the newer version from your Time Machine back up. Just click the Time Machine icon in the menu bar and select Enter Time Machine. You can now navigate to the most recent backup and the files you want and retrieve them.

If you used another tool to back up your files, use its restore facility. If you copied them manually, copy them back.

What to do if your backup is in a newer version of macOS

If your backup is a later OS than the one you've just installed, migrating data could lead to compatibility problems.

If, however, you have a clone of your Mac's startup drive from before you upgraded, you could migrate data from that. You'd still be without the files you created while running the newer OS, but you'd at least have a base from which to start.

You would then manually copy files created while you were running the newer OS from the backup you made before you wiped your Mac's startup disk.

How to downgrade without a Time Machine backup

If you didn’t make a back up prior to upgrading, it is still possible to downgrade, but it’s a little more complicated.

One way you can downgrade is with a bootable installer, we describe how below. We explain how to create a bootable installer of macOS here.

If you don’t have the version of Mac OS you need here’s how to get an old version of Mac OS X.

Downgrade Mac OS X using a bootable installer

If you have a bootable installer of the version of Mac OS X you want to revert to, you are all set to install the older version of the MacOS. Note that this will involve erasing your startup drive, so make a backup of anything you don’t want to lose first. You cannot install a newer version of macOS over any later operating system so your startup volume has to be erased first.

  1. Shut down your Mac
  2. Plug in the external drive that contains your bootable installer
  3. Start up the Mac holding down the Option/Alt+R while it is booting up.
  4. When your Mac starts up it will be in Recovery mode and you’ll see a macOS Utilities screen showing the following options: Restore from Time Machine Backup, Reinstall macOS, Get Help Online and Disk Utility
  5. Select Disk Utility
  6. Click continue
  7. Select your Startup Disk
  8. Click on Erase. You need to choose one of the Mac OS Extended (Journaled) formats
  9. Now that the startup volume has been erased, restart your Mac holding down Alt/Option and select the external USB drive
  10. Now you should be able to install the older version of the operating system using that external installer

Run two versions of MacOS on your Mac

Another option is to create a partition so that you can run both versions of the Mac operating system on your Mac. Read about how to install multiple versions of MacOS on your Mac here.

Fixing common problems

Reversing an upgrade carries with it a number of wrinkles and pitfalls.

Most of these are due to changes in file formats and settings between versions of the OS. So, for example, if you create a document or work on a file in a new version, whether it's a beta or full release, of macOS and then try and open it in an older version, it may not work.

To mitigate this, it's wise to export any documents you've created or worked on in the newer OS in a standard file format. So, for example, if you use Scrivener or Ulysses, export documents as RTF files. That way, if the native files don't survive the reverse upgrade, you'll be able to re-import the RTF files.

Take screenshots of preferences and settings

Whenever you perform a clean install of macOS, which is what you're doing here, it's a good idea to take screenshots of any custom settings you've created in apps or in System Preferences. That makes it easier to re-create them later.

You should also make a note of user account and password details for anything you've set up while running the new version of the OS. If you don't use iCloud or Chrome to synchronise bookmarks, it's a good idea to export those and make a copy.

How to remove macOS Sierra and downgrade to El Capitan: Export bookmarks

And unless you're using the migrate data option outlined above, you'll also need installers and licence codes for apps you use. If those are downloads from the Mac App Store, you can just re-download them from the Purchased section in the App Store. If not, make sure you can download them from the vendor's website. If you don't use a password manager to store licence codes, make sure you've got a copy of them before you start.

Synchronise

If you use Dropbox, OneDrive, Google Drive or any other form of cloud storage, make sure your data is in sync before you start the process of reversing an upgrade. It's easy to forget that the files that live in your Dropbox folder, or example, are local files and that while synchronisation is frequent, the loss of an internet connection will prevent it and you could have files in your local folder that haven't yet been copied to the cloud.

Clicking on the cloud service's logo in your menu bar should tell you whether synchronisation completed successfully and files are up to date.

If you use Gmail, iCloud mail or any other IMAP server for your email, make sure it's up to date and any drafts you've composed recently have been synchronised. If you use a POP3 account you'll have to manually back up the mail database and restore it after you reverse the upgrade. Or, if you only have a few messages you need to keep, forward them to a Gmail account - you could set one up especially for that purpose.