How to Perform a Clean Installation of macOS 10.14 Mojave

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Apr 12, 2001
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This article guides you through the process of performing a clean installation of macOS 10.14 Mojave using the bootable USB drive method, rather than upgrading your Mac using Apple's standard installation package, which retains existing user data and any user-installed apps.


Creating a bootable USB drive provides you with a convenient way to install a fresh copy of macOS Mojave on multiple Macs. Performing a clean install can also remove annoying quirks and strange behaviors that your Mac may have inherited over time, and often helps to reclaim disk space caused by junk files left by third-party apps.

The following procedure works with the latest public beta of macOS Mojave, which you can download by enrolling in the Apple Beta Software Program. It will also work with the final version of Mojave, once it's released in the fall. To follow the steps, you'll need an empty 8GB or larger USB thumb drive (USB-C or USB-A, depending on your Mac) and an hour or two of downtime while the installation procedure completes.

Also, be sure to perform a full backup of your Mac beforehand using Time Machine, so that you can restore your original system from the Recovery partition if something goes wrong.


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Article Link: How to Perform a Clean Installation of macOS 10.14 Mojave
 

SkimPappa

macrumors member
Nov 23, 2016
43
73
It wouldn’t let me format to APFS. Required Mac OS extended. Is there a trick to using APFS ?
 

archvile

macrumors 6502
Oct 27, 2007
463
596
Does this method enable encryption by default? (Assuming it formats as APFS)? If not, does FileVault still have to be enabled separately? I thought APFS was encrypted by default, or is that only in newer 2016+ machines?
 

rroch

macrumors newbie
Nov 15, 2016
10
28
I think this process erases your user data, which is the meaning of "clean install" of course. But could you please edit this (otherwise great) article for the sake of any novice who might think that this process is equivalent to a regular upgrade (by misunderstanding "rather than upgrading your Mac using Apple's standard installation package"). The words "be sure to perform a full backup of your Mac beforehand using Time Machine. That way you can restore your system from the Recovery partition if something goes wrong" [my bold] could also lead a novice to think that the backup is just in case something goes wrong, when in fact it will needed if you want to restore your user data. Or did I get something wrong, and this process actually does not erase user data?
 
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JosephAW

macrumors 68040
May 14, 2012
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I'm hoping that Mojave will be the Snow Leopard of macOS. High Sierra was a dud and Sierra was fair so I'll stay on El Capitan until something more stable and compatible comes along.
Mojave will probably be my last macOS after they migrate from x86 to AxFuzion MBPs.
 
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Mr. Dee

macrumors 68030
Dec 4, 2003
2,577
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I'm keeping my MacBook Pro on Sierra as long as I can. Will switch to High Sierra when Apple and Microsoft drops support for it.
 

Soterman

macrumors newbie
Jul 20, 2016
6
8
I personally prefer using Disk Utility to create a brand new partition and initiating the Mojave installer from the existing High Sierra partitions... It is the equivalent of a clean install and I have found no drawbacks so far...
 
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jonnysods

macrumors 604
Sep 20, 2006
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I'm hoping that Mojave will be the Snow Leopard of macOS. High Sierra was a dud and Sierra was fair so I'll stay on El Capitan until something more stable and compatible comes along.
Mojave will probably be my last macOS after they migrate from x86 to AxFuzion MBPs.

Same here. HS misbehaved way more than any other build of OSX for me. I'm on Mojave PB to get away from it! Still on Sierra on my family computer.
 

timmyh

Contributing Editor
Mar 18, 2016
145
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Edinburgh, UK
I think this process erases your user data, which is the meaning of "clean install" of course. But could you please edit this (otherwise great) article for the sake of any novice who might think that this process is equivalent to a regular upgrade (by misunderstanding "rather than upgrading your Mac using Apple's standard installation package"). The words "be sure to perform a full backup of your Mac beforehand using Time Machine. That way you can restore your system from the Recovery partition if something goes wrong" [my bold] could also lead a novice to think that the backup is just in case something goes wrong, when in fact it will needed if you want to restore your user data. Or did I get something wrong, and this process actually does not erase user data?

Thanks for your comment, rroch. I've added a line in the first paragraph to clarify the difference between a 'clean installation' and a standard upgrade.
 

Aquaporin

macrumors 6502
Jun 27, 2005
441
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USA
What’s the best way to do a clean install and preserve your applications and media? Copy over from an external HD or restore with Time Machine after clean install?
 

maflynn

Moderator
Staff member
May 3, 2009
67,072
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Boston
That was a publicized feature of Mojave and has been functional in the betas for a few months.
I was unaware of this - thanks for the confirmation. I'm running HS, so its not something I was keenly paying attention too.
 
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