How to rollback the MacOS Sierra beta to OS X El Capitan

Get rid of the Sierra beta and return to the warm embrace of El Capitan.

Matt Elliott Senior Editor
Matt Elliott is a senior editor at CNET with a focus on laptops and streaming services. Matt has more than 20 years of experience testing and reviewing laptops. He has worked for CNET in New York and San Francisco and now lives in New Hampshire. When he's not writing about laptops, Matt likes to play and watch sports. He loves to play tennis and hates the number of streaming services he has to subscribe to in order to watch the various sports he wants to watch.
Expertise Laptops, desktops, all-in-one PCs, streaming devices, streaming platforms
Matt Elliott
2 min read
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If you installed the public beta of MacOS Sierra to give it a spin but have now satisfied your curiosity, you can return to OS X El Capitan while you await Sierra's final release this fall.

If you followed my earlier advice to install the Sierra beta on a partition, then it's easy to erase and remove that partition. And if you took the bold step to install the Sierra beta right over El Capitan, then you'll need to roll back the clock and use a Time Machine backup that predates your installation of the Sierra beta. Hopefully, you followed my advice to create a Time Machine backup before installing the Sierra beta.

Erase and remove partition

Before you remove Sierra, make sure you move any files you may need from that partition to an external drive or a cloud service, including iCloud Drive. (I had a few files I wanted to save from my Sierra partition and simply opened Finder and dragged them to the iCloud Drive folder.)

To erase the partition on which you installed Sierra, you first need to restart your Mac and while it's restarting, hold down the Option key so you can choose which partition to start. Choose the partition with El Capitan.

  • After El Capitan boots up, open Disk Utility
  • On the left panel, select the partition you created for the Sierra beta
  • Click the Erase button at the top of Disk Utility
  • When the confirmation window pops up, click Erase to confirm your intentions.
Screenshot by Matt Elliott/CNET

With the data erased from your partition, you still need to delete the now-empty partition in order to reallocate its space to the rest of your hard drive.

  • Select the top-most drive from the left panel
  • Click the Partition button at the top
  • On the pie graph on the left, click the wedge that represents the partition you just erased.
  • Click the "-" button and then click Apply.
Screenshot by Matt Elliott/CNET

After a minute or so, Disk Utility will finish applying changes to your drive and deem the operation successful. Click Done to complete your work here.

Time Machine backup

If you installed the MacOS Sierra beta over El Capitan, it's time to dig out your Time Machine drive and get to work.

  • Connect the external drive you use for Time Machine backups.
  • Restart your Mac and hold down Command-R as it boots up to enter recovery mode.
  • From the Utilities window, select Restore From Time Machine Backup.
  • Select the most recent OS X 10.11 backup and click Continue.
  • Select the destination for your backup, which is usually Macintosh HD unless you renamed it.

Time Machine will restore your Mac to this point and you'll again be running OS X El Capitan.

While you await Sierra's final release this fall, you can get Sierra's beautiful wallpaper on your desktop.