How to Create macOS Monterey ISO File?

by Admin

macOS Monterey aka macOS 12 was announced on WWDC21. The new macOS has brought tons of new features and made it way better as compared to previous versions. Monterey looks goods, has improved user experience with tons of new features.

Still, you are here with me to create a macOS Monterey ISO file. There can be many reasons, either you want to install macOS Monterey on VMware workstation or want to install macOS Monterey on Virtual Box or you want to use the ISO file and install macOS Monterey on PC; no matter what the reason is.

Here is how to create a macOS Monterey ISO file for free. To create a macOS Monterey ISO file, you will need macOS Monterey Installer.app.

Table of Contents

How to Create macOS Monterey ISO file using terminals?

You can download macOS Monterey Installer.app from the Apple server directly or can use third-party applications or servers. Third-party application as gibmacOS can help you to download macOS Monterey Assistant Package.

Here is also a direct link to download macOS Monterey Assistant.pkg.

Download macOS Monterey Assistant.pkg

No matter from which source you are going to download, it will work. perform the installation by Open > Continue > Agree > Install > Enter your Password > Install software > Close. Now, for downloading macOS Monterey, a new window will appear. You can start the download by clicking on Upgrade Now. The download might take a while, so be patient.

Once the download is completed, make sure you have quitted the installer by Install macOS Monterey > Quit Install macOS or use the shortcut key Command + Q.

Launch Terminal

First thing first, you will need to open your terminal. You can open the terminal by clicking on Launchpad and type Terminal. Soon terminal will appear. Now, type the command given below to start the creation of the macOS Monterey ISO file.

Create an empty disk image

This command will create an empty disk image of Monterey with the size of 16500 MB with the name of Monterey.dmg. on the creation of the disk image, the password will be asked; type your Password.

Sudo hdiutil create -o /tmp/Monterey -size 16500m -volname Monterey -layout SPUD -fs HFS+J

Mount the disk image

Here you will need to mount the Monterey disk image file to Volume/Monterey. Let’s continue to the terminal to make things easier. Type the following:

Sudo hdiutil attach /tmp/Monterey.dmg -noverify -mountpoint /Volumes/Monterey

Create bootable USB drive

In this step, you will need to use createinstallmedia to make create a bootable USB drive. For the creation typing, Sudo is a must, or else won’t work. So, open the Application Directory, right-click on macOS 12 installer then Show Content Package> Contents > Resources, and there you will find the createinstallmedia. Now drag it to the terminal.

sudo /Applications/Install\ macOS\ 12\ Beta.app/Contents/Resources/createinstallmedia –volume /Volumes/Monterey –nointeraction

Detach the disk image

Applying the codes will erase anything on your Big Sur disk image and starts the installation of macOS Monterey. Type the following to detach the disk image.

hdiutil detach /Volumes/Install\ macOS\ 12\ Beta

Covert DMG file of Monterey to ISO

It is time to convert the DMG file to CDR. Once the DMG is converted to CDR then we will again convert it to an ISO file. First, convert the DMG to CDR then move it to the desktop by typing the following:

hdiutil convert /tmp/Monterey.dmg -format UDTO -o ~/Desktop/Monterey.cdr

now change it to an ISO file by using the command below:

mv ~/Desktop/Monterey.cdr ~/Desktop/Monterey.iso

sudo rm -rf /tmp/Monterey.dmg

Note: using commands as rm –rf on the terminal will delete any file on your disk image or /tmp folder. Even though, if you won’t use the last command; still, the unnecessary files in /tmp folder will be deleted.

So, here is a quick review of the step you will need to create macOS Monterey ISO file:

Launch Terminal
Create an empty disk image
Mount the disk image
Create bootable USB drive
Detach the disk image
Covert DMG file of Monterey to ISO

Here how your entire terminal will look like after using all the commands and creating a macOS Monterey ISO file.

myoshub@myoshub-Mac ~ % hdiutil create -o /tmp/Monterey -size 16500m -volname Monterey-layout SPUD -fs HFS+J

hdiutil: create: Only one image can be created at a time.

Usage: hdiutil create <sizespec> [options] <imagepath>

hdiutil create -help

myoshub@myoshub-Mac ~ % hdiutil create -o /tmp/Monterey -size 16500m -volname Monterey -layout SPUD -fs HFS+J

created: /tmp/Monterey.dmg

myoshub@myoshub-Mac ~ % hdiutil attach /tmp/Monterey.dmg -noverify -mountpoint /Volumes/Monterey

/dev/disk3 Apple_partition_scheme

/dev/disk3s1 Apple_partition_map

/dev/disk3s2 Apple_HFS /Volumes/Monterey

myoshub@myoshub-Mac ~ % sudo /Applications/Install\ macOS\ 12\ Beta.app/Contents/Resources/createinstallmedia –volume /Volumes/Monterey –nointeraction

Erasing disk: 0%… 10%… 20%… 30%… 100%

Making disk bootable…

Copying to disk: 0%… 10%… 20%… 30%… 40%… 50%… 60%… 70%… 80%… 90%… 100%

Install media now available at “/Volumes/Install macOS 12 Beta”

myoshub@myoshub-Mac ~ % hdiutil detach /Volumes/Install\ macOS\ 12\ Beta

“disk3” ejected.

myoshub@myoshub-Mac ~ % hdiutil convert /tmp/Monterey.dmg -format UDTO -o ~/Desktop/Monterey.cdr

Reading Driver Descriptor Map (DDM : 0)…

Reading Apple (Apple_partition_map : 1)…

Reading (Apple_Free : 2)…

Reading disk image (Apple_HFS : 3)…

………………………………………………………………………….

Elapsed Time: 1m 31.065s

Speed: 146.6Mbytes/sec

Savings: 0.0%

created: /Users/myoshub/Desktop/Monterey.cdr

myoshub@myoshub-Mac ~ % mv ~/Desktop/Monterey.cdr ~/Desktop/Monterey.iso

How to Create macOS Monterey ISO File?