macOS Sierra

If you decide macOS High Sierra just isn't working for you, you can downgrade back to Sierra.

macOS High Sierra is the next major operating system for Mac — but just because you take a new operating system for a whirl doesn't mean you're ready to commit full-time just yet. If you've decided you'd rather return to macOS Sierra, you can downgrade with just a few steps. It is a bit of a complex process, but if you follow the steps you'll be back to your old setup in no time.

Note: If you are reading this article on the Mac that you want to downgrade on, switch to another device or print this page before continuing so you can read along as you go.

Step 1: Back up your Mac

This process will erase macOS High Sierra from your hard drive entirely. That means any files, programs, or documents you've been working on while using macOS High Sierra will also be erased if you don't back them up first. Use an external hard drive or a cloud-based program like DropBox, OneDrive, or iCloud. If you don't save these important files somewhere off of your computer you will lose them.

Step 2: Create a bootable drive of macOS Sierra

Before you erase macOS High Sierra from your computer, download macOS Sierra from the Mac App Store. It should be in your purchase list, or you can simply search for it in the Mac App Store. You'll need a copy of macOS Sierra in order to downgrade from macOS High Sierra.

When the final version of macOS High Sierra goes live, macOS Sierra will no longer be available in the App Store, so make sure you download Sierra before High Sierra launches.

Note: Making a bootable installer requires the use of Terminal. If you don't feel comfortable making changes to your Mac with Terminal, you can create a bootable disk using the DiskMaker X program.

Step 3: Erase macOS High Sierra

  1. Connect your Mac to the internet via Wi-Fi or Ethernet.
  2. Click on the Apple icon in the upper left corner of the screen.
  3. Select Restart from the dropdown menu.

    Restarting Mac

  4. Hold down Command+R, and keep holding the keys until your computer reboots. This will put your computer into Recovery Mode.
  5. Click on Disk Utility in the OS X Utilities selector.
  6. Click Continue.

    Seleting Disk Utilities from the OS X Utilities Selector

  7. Select your Startup Disk.
  8. Click on the Erase tab at the top of the window.

    Selecting a drive to erase on Mac

  9. Enter a name for the file to be destroyed (Like macOS High Sierra or something).
  10. Select Mac OS Extended (Journaled) from the format list.
  11. Click Erase.

    Erasing a drive on Mac

After the process is complete, quit Disk Utility from the dropdown menu in the upper left corner of the screen to go back to the OS X Utilities selector.

Step 4: Reinstall macOS Sierra

After you have erased macOS High Sierra, you will want to reinstall an earlier operating system.

  1. Connect your Mac to the internet via Wi-Fi or Ethernet.
  2. Click on the Apple icon in the upper left corner of the screen.
  3. Select Restart from the dropdown menu.

    Restarting Mac

  4. Hold down Option while your computer restarts. This will send you to the option to select a startup disk.
  5. Select macOS Sierra from the list of startup disk options. macOS Sierra will begin installing on your Mac.
  6. Click Continue in the macOS Sierra installation window.

macOS Sierra will install like a standard update. You will agree to the licensing terms before the software reboots on your Mac.

Note: Depending on how old your Mac is, you may download an older version of OS X, possibly the one that originally shipped with your computer (especially if you end up in Internet Recovery Mode). If that happens, complete the installation of the older operating system (IE. Mavericks or Yosemite). Once the installation is complete, open the Mac App Store and download macOS Sierra from your Purchased list.

Step 5: Restore data from an earlier macOS Sierra Time machine backup

If you have a recent backup of your Mac saved via Time Machine (which you should), you can use it to reinstall macOS Sierra.

  1. Connect your Mac to the internet via Wi-Fi or Ethernet
  2. Click on the Apple icon.
  3. Select Restart from the dropdown menu.

    Restarting Mac

  4. Hold down Command+R when you hear the startup chime and keep holding the keys until your computer reboots.
  5. Select Restore from Time Machine Backup in the OS X Utilities selector.
  6. Click Continue.

    Selecting restore from backup from the OS X Utilities Selector

  7. Click Continue after reading the important information about restoring from a backup.
  8. Select the Backup source for where your Time Machine backup is stored.
  9. Click Continue.
  10. Select the most recent macOS Sierra backup on the drive.
  11. Click Continue.

    Steps to restore from backup on Mac

Your Mac will begin restoring from the Time Machine backup and then reboot. This process can take a while, so grab a cup of coffee while you wait.

If you run into any problems while trying to downgrade your Mac operating system, let us know in the comments.