Creating a bootable macOS Sequoia USB installer is a straightforward process that allows you to install or repair macOS Sequoia (version 15.x) on a compatible Mac, or use it for troubleshooting or clean installations.
This guide uses built-in macOS tools, specifically the createinstallmedia command, to transform a USB drive into a bootable installer.
Below are detailed step-by-step instructions tailored for macOS: –
A video describes How to create a bootable macOS Sequoia USB installer?
Prerequisites
macOS Sequoia Installer: The full Install macOS Sequoia.app (~12-14GB) located in /Applications. See Step 1 for how to obtain it if missing.
USB Drive: Minimum 16GB capacity (32GB recommended for reliability). A USB 3.0/3.1 drive speeds up the process.
Mac with Admin Access: A Mac running macOS 10.13+ (High Sierra or later) with an admin account.
Free Space: ~20GB on the Mac for temporary files.
Time: ~20-30 minutes, depending on USB speed.
Step-by-Step Instructions
Step 1: Obtain the macOS Sequoia Installer
Check for Installer:
Open Finder, navigate to /Applications, and look for Install macOS Sequoia.app.
Verify its size (should be ~12-14GB): du -sh /Applications/Install\ macOS\ Sequoia.app
Download if Missing:
Mac App Store (Supported Macs):
On a compatible Mac (e.g., 2018 MacBook Air or later), open the App Store.
Search for “Sequoia” (availability depends on your host macOS—may redirect to Software Update).
Click “Get” to download to /Applications.
Software Update Command (Alternative):
In Terminal: softwareupdate --fetch-full-installer --full-installer-version 15.0
Downloads Install macOS Sequoia.app to /Applications.
gibMacOS (Unsupported Macs or Older Hosts):
Open Terminal: /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" brew install python git clone https://github.com/corpnewt/gibMacOS.git cd gibMacOS python3 gibMacOS.command
Select “macOS Sequoia” (15.x), download the .pkg, and extract: pkgutil --expand-full "macOS Downloads/publicrelease/InstallAssistant.pkg" ~/Desktop/SequoiaInstaller mv ~/Desktop/SequoiaInstaller/Applications/Install\ macOS\ Sequoia.app /Applications/
Move if Needed:
If downloaded elsewhere: mv ~/Downloads/Install\ macOS\ Sequoia.app /Applications/
Step 2: Prepare the USB Drive
Insert USB Drive:
Plug it into your Mac. It should appear in Finder or on the Desktop.
Go to Applications > Utilities > Disk Utility, or use Spotlight (Command + Space, type “Disk Utility”).
Erase the USB Drive:
In Disk Utility, select the USB drive in the left sidebar (top-level device, e.g., “16.0 GB SanDisk”, not a partition).
Click Erase and configure:
Name:SequoiaUSB (or any name).
Format:Mac OS Extended (Journaled) (required for the bootable installer).
Scheme:GUID Partition Map.
Click Erase. Warning: This wipes all data—back up anything important.
Verify Mount Point:
After erasing, it mounts as /Volumes/SequoiaUSB. Confirm: ls /Volumes/
Step 3: Create the Bootable Installer
Run createinstallmedia:
Open Terminal (Applications > Utilities > Terminal).
Enter this command, replacing SequoiaUSB with your USB’s volume name if different: sudo /Applications/Install\ macOS\ Sequoia.app/Contents/Resources/createinstallmedia --volume /Volumes/SequoiaUSB --nointeraction
Breakdown:
sudo: Admin privileges.
--volume: Specifies the USB.
--nointeraction: Runs without prompts.
Enter your admin password (it won’t display) and press Enter.
