How to Create macOS Sequoia ISO: 8 Easy Steps

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Creating a bootable macOS Sequoia ISO file is an essential task for developers, IT administrators, or anyone who needs to install the OS on a virtual machine (like VMware or VirtualBox) or create a permanent installation disk. Unlike Windows, Apple doesn’t provide a direct ISO download, so you have to make one yourself from the installer app.

If you wish to directly download the Seuqoia ISO file, we have already created it for you:
Download macOS Sequoia ISO File for VirtualBox and VMware

This guide will walk you through the process in 8 straightforward steps using built-in macOS Terminal commands.

Prerequisites:

A Mac compatible with macOS Sequoia.
At least 20-25 GB of free storage space.
A reliable internet connection is required to download the installer.

Step 1: Download the macOS Sequoia Installer Package

Download InstallAssistant.pkg from our website archive.

At the time of writing this article, we are currently running macOS Sequoia 15.6.1. So, you can download the InstllAssistant.pkg file of the same version as shown in the screenshot below.

How to Create macOS Sequoia ISO: 8 Easy Steps

Step 2: Install the macOS Sequoia Application

Note: The provided step mentioned “Tahoe,” which appears to be a typo. The correct name for the new OS is Sequoia. The download in Step 1 automatically places the “Install macOS Sequoia.app” in your Applications folder. This step is complete once the download finishes.

Step 3: Create a Blank Disk Image

We need a container to build the bootable installer. Open Terminal (found in Applications/Utilities/) and paste the following command:

hdiutil create -o ~/Desktop/Sequoia -size 20000m -volname Sequoia -layout SPUD -fs HFS+J

Explanation: This command creates a 20GB (~20000m) blank disk image named Sequoia.dmg on your Desktop, formatted as macOS Journaled (HFS+J).

Step 4: Mount the Disk Image

Next, we need to mount this new image so the system can see it as a usable volume. Run this command in Terminal:

hdiutil attach ~/Desktop/Sequoia.dmg -noverify -mountpoint /Volumes/Sequoia

Explanation: This attaches the Sequoia.dmg file and makes it available at the mount point /Volumes/Sequoia.

Step 5: Create the Bootable Install Media

This is the most critical step. Using Apple’s hidden createinstallmedia tool, we will copy the necessary boot files into our mounted volume. Enter this command, and be prepared to enter your administrator password:

If using the Public version:

sudo /Applications/Install\ macOS\ Sequoia.app/Contents/Resources/createinstallmedia --volume /Volumes/Sequoia --nointeraction

If using Beta version:

sudo /Applications/Install\ macOS\ Sequoia\ beta.app/Contents/Resources/createinstallmedia --volume /Volumes/Sequoia --nointeraction

Explanation: The sudo command requires your password to grant root privileges. The tool erases the mounted volume and copies the installer contents to it, making it bootable. The --nointeraction flag skips the confirmation prompt.

Step 6: Unmount the Volume

Once the process in Step 5 is complete (it will take 10-20 minutes), you need to unmount the volume. However, note that the volume name changes during the process. Use this command:

If you are using the Public version:

hdiutil detach /Volumes/Install\ macOS\ Sequoia

If you are using the Beta version:

hdiutil detach /Volumes/Install\ macOS\ Sequoia\ beta

The volume name is now “Install macOS Sequoia”, not just “Sequoia”.

Step 7: Convert the DMG to a CDR (ISO) Format

Now, convert the finalized .dmg file into a format recognizable by most virtualization software as an ISO.

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

Explanation: The -format UDTO option tells hdiutil to create a CDR (DVD/CD Master) file, which is functionally identical to an ISO.

Step 8: Rename the CDR to ISO

Finally, simply rename the file extension from .cdr to .iso using the mv (move) command.

mv ~/Desktop/Sequoia.cdr ~/Desktop/Sequoia.iso

Congratulations! You now have a fully bootable Sequoia.iso file on your Desktop, ready to be used with virtualization software or burned to a physical DVD.

Complete Video Tutorial:

How to Use Your New macOS Sequoia ISO File

The primary use for this ISO is virtualization. Here’s how to get started:

In VMware: Create a new virtual machine. When prompted to select an operating system, choose “Use a different disc or disc image” and point it to your new Sequoia.iso file. You can follow this guide: How to Install macOS Sequoia on VMWare on Windows PC
In VirtualBox: Create a new VM, select “macOS” as the type, and when asked for a startup disk, click the folder icon to select your Sequoia.iso file.

Important Disclaimer: Running macOS virtually on non-Apple hardware is against Apple’s End User License Agreement (EULA). This guide is intended for use on Apple hardware for purposes like testing and development.