Backing up Your Mac Before a Clean Install of macOS

Back up your data locally

This is why the first step of a clean install is data backup. Using the built-in local backup feature, Time Machine, you can save all the data from the Mac on an external hard drive. This way you’ll back up important data, files and pictures so you can access them after the clean install. We recommend Time Machine for a complete system backup.

If you don’t mind the extra time and care, it’s also recommended that you use an additional hard/flash drive to store just the data you will copy back to the ‘refreshed’ Mac.

Back up data using Cloud services

Starting with macOS Sierra, a deeper integration with Apple’s iCloud service made cloud backups seamless on a Mac. By signing in with your Apple ID, you can have all the files stored in the Desktop and Documents folders stored automatically in iCloud Drive. That way you’ll have a saved version in the cloud that also becomes available on all your other Macs or iOS devices. The catch is having enough iCloud storage, and this means you may need to opt for a paid iCloud storage tier. However, we do highly recommend using iCloud Drive.

The convenience of using iCloud Drive with macOS Sierra is that, after the clean install, you’ll easily retrieve all your documents back on your Mac without the need to attach an external drive to copy them back. You will still need to manually install your applications, but hey, that’s what a lean install is about: a fresh (re)start.

Optimizing backups

Before hitting the backup button on Time Machine, just consider this: do you really want to back up all those trash and junk files that have built up over time? Have you checked whether you have duplicate files occupying precious disk space?

Optimizing a backup is also important, since you will spare the backup drive and the refreshed Mac from unnecessary data. Third party Mac optimization apps can help you with this task and reduce the need for the tedious job of a clean install, since they remove all system junk and run various scripts to keep the computer in its best shape.