With the aforementioned apps, you can even schedule the creation of a bootable backup every night, so that you’ll always have a fallback regardless of what goes wrong.Changes in macOS security since Mojave have been deep and extensive, but their impact on troubleshooting isn’t often appreciated. Obviously, the bootable backup strategy doesn’t help if you’ve already upgraded, but it’s something to consider adding to your maintenance routine to help prevent issues in the future. If you upgrade and find that you don’t like the new version of macOS, or if there are issues with application compatibility, you can simply revert to your bootable backup and be back up and running with the old operating system in a matter of minutes. This not only makes normal system recovery much easier, but it also allows you to grab a “snapshot” of your system just before major macOS upgrades. Using an app like Carbon Copy Cloner or SuperDuper you can create full bootable backups of your drive. Then back up all of your data, boot to the USB installer and use Disk Utility to erase the drive, and then install High Sierra from scratch.įor those who don’t like the sound of that, but still fear needing to downgrade, one forward-looking solution is to get into the habit of creating bootable backups of your Mac’s primary drive.

To do so, you’d need to use the steps above to download the High Sierra installer and create a bootable USB. You see, there’s no built-in, official way to downgrade nondestructively from one macOS version to another.

Reasons for doing so may include downloading an installer for another Mac that has limited or no Internet access, troubleshooting another Mac that won’t boot, or even creating a bootable installer for the purpose of downgrading your own Mac if you find that software you rely on has incompatibilities with the latest version of macOS. While Apple would justify this limitation in the name of simplifying things for consumers, the fact remains that many users may still need to download an older version of macOS at some point. The idea is that once you upgrade to the latest version of macOS there’s no going back to using an earlier version. For example, once you’re running macOS Mojave, you won’t see the macOS High Sierra page listed in the Mac App Store, nor will it show up in App Store search results. How to Download macOS High Sierra From macOS MojaveĮver since Apple started using the Mac App Store to distribute operating system updates, the company hasn’t made it particularly easy to access older versions of macOS.

Install mac os high sierra app