How to create a macOS 12 Monterey installer on an external drive

Having an external USB installer drive allows you to install the OS to multiple computers without re-downloading it, perform clean installs instead of initiating them from within an existing OS, and boot to the installer’s built-in recovery for troubleshooting tools. This tutorial shows you how to create an install drive for macOS Monterey.

"macOS Monterey" written on the official macOS Monterey wallpaper

Check out: How to make a macOS Ventura USB installer and use it to get macOS 13 on your Mac

What you need

  • External storage drive of 16 GB or larger. A USB stick/pen drive is usually best for this, but you can also use an SD card (if your Mac has an SD card slot), a partition on a larger external hard drive, or another kind of external storage drive.
  • Reliable internet connection

Note: This guide describes the installer creation process for the beta as well as the stable release installer. As usual, all beta testing is at your own risk. Do not install beta operating systems to work-critical machines, especially without making full backups first.

How to create a macOS Monterey installer

1) For most users, who wish to create an installer from the general release version of the OS, download a copy of macOS Monterey from the Mac App Store.

If you wish to create a beta installer instead, users with a paid Apple Developer account can download the Beta Access Utility from the downloads section of their Apple Developer account page. Once installed, open System Preferences > Software Update to view and download the beta.

Other users can join the Public Beta for free and will receive beta releases on a slightly delayed schedule. Public Beta users will be provided with a slightly different version of the Beta Access Utility. Once installed, open System Preferences > Software Update to view and download the beta.

2) When your download is complete, your Mac will launch the macOS 12 installer app. We do not want to install it now, so quit it, open your Applications folder and locate the installer in there. Don’t rename it or move it out of Applications.

3) Format your 16GB drive to GUID Partition Map and Mac OS Extended (Journaled) in Disk UtilityThis guide explains how, if you are not familiar with the method. Note: All data on the external drive will be erased.

Format USB drive in Mac OS Extended Journaled format

4) Name the newly formatted drive USB for ease. (Use all uppercase alphabets.)

5) Next, launch the Terminal application.

Users who downloaded the release version of macOS Monterey can now paste in this command:

sudo /Applications/Install\ macOS\ --volume /Volumes/USB --nointeraction

Users who downloaded the beta version of macOS Monterey should paste in this command instead:

sudo /Applications/Install\ macOS\ Monterey\ --volume /Volumes/USB --nointeraction

  • Remove “–nointeraction” from the command to be asked for confirmation before erasing the external drive.
  • The “–downloadassets” flag was introduced with macOS Mojave. It supposedly downloads on-demand assets which may be required during installation. This is presumably helpful for offline installations, though I’ve never noticed any difference in online or offline installations when using it. I wouldn’t bother with it, but add it if you like.
  • Older versions of macOS used an “–applicationpath” flag in this command, but this is now deprecated and will cause an error if used. Use the command we have provided above instead of referring to guides that were written for previous versions of macOS.

6) Press enter to issue the command, and type your password when prompted (you won’t see the password being typed in Terminal).

Create macOS Monterey USB bootable drive using Terminal

Terminal will provide a readout of the external drive being erased and of the installer files being copied onto it. When Terminal declares that the drive has been created, locate it on your desktop under Install macOS Monterey or Install macOS Monterey beta.

Using Terminal to create macOS Monterey bootable drive

How to use the macOS Monterey installer

If you have a Mac with Apple silicon (like M1, M1 Pro, M1 Max, M1 Ultra, or M2), follow the steps shown here.

And if your Mac has an Intel processor, follow these steps below:

1) Shut down the computer you wish to install the OS on and insert your newly-created external installer drive.

2) Start up the computer while holding down the Option key.

3) The Startup Manager will show a list of bootable drives. Select Install macOS Monterey to boot from the installer.

4) You can now continue to install as you like.

The installer also allows you to reformat connected drives and access tools such as Terminal, Startup Disk, and Firmware Password Utility.

macOS Monterey running on an Intel Mac

Have fun using Apple’s macOS Monterey!

Remember: back up your data before upgrading to a new OS, particularly a beta one. Your installer drive can be used to troubleshoot your Mac if it becomes corrupted and can’t boot from its own Recovery partition. Being able to reinstall your operating system or open a Terminal session from the external drive is also extremely useful in a pinch.

I mainly use these drives to install macOS to multiple computers without having to re-download the installer onto each one, saving time and data. If you need any help with the guide, ask your question in the comments below!

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