How to Downgrade macOS High Sierra

How to Downgrade macOS High Sierra

Some MacOS High Sierra 10.13.x users may wish to downgrade back to macOS Sierra 10.12.x or even Mac OS X El Capitan. Mac users can downgrade from High Sierra to a prior Mac OS release, either by formatting the hard drive and clean installing Sierra or another prior system release, or by relying on a Time Machine backup made prior to the update to macOS High Sierra. The downgrade method well cover here uses a Time Machine backup to restore to a prior version of macOS and downgrade macOS High Sierra 10.13. If you do not have a Time Machine backup made with a previous version of Mac OS, this will not be possible to follow. For most users, they should not downgrade from macOS High Sierra. Downgrading system software is probably most appropriate as a last resort or a final troubleshooting method, if some particular problem with High Sierra is making the Mac unusable or incompatible with your workflow.

There are mixed reports of some Mac users updating to macOS High Sierra and then experiencing a range of problems, from rapid battery life draining, inability for some apps to open, apps crashing, strange performance problems or overall performance degradation, problems with mounting and reading disks, problems with networking connectivity and wi-fi, amongst other issues that could be considered deal breakers.

Keep in mind there is no official downgrade path for macOS. Downgrading macOS High Sierra is accomplished by formatting the target hard drive, thereby erasing everything on it, then restoring from a prior Time Machine backup, or by formatting and then clean installing a prior version of macOS system software onto the computer, and then manually restoring files from some other backup. For our purposes here we will be covering a downgrade by erasing, then restoring from a Time Machine backup made prior to installing High Sierra. .

Backup your Mac before beginning this process, it requires erasing the hard drive and removing all data. The restore of macOS will begin, this can take quite some time depending on the size of the backup, the speed of the hard drive, amongst other factors. Be prepared to wait a while, and let the entire process complete uninterrupted.

When the restore from Time Machine completes, the Mac will boot back up to the state and with the system version where the restored Time Machine backup was made. Note that if the process of formatting the hard drive mentioned above is usually only necessary for Mac users who changed their file system to thew new AFPS file system available in macOS High Sierra. If the Mac file system was not changed then a regular old is possible without bothering with the additional step to format the drive, but nonetheless the data on the driven will be removed and replaced with the data on the Time Machine backup.