When creating bootable USB installation drives, provisioning multiple corporate Macs, or setting up virtual machines in Parallels or UTM, having a complete, standalone macOS installer application (such as “Install macOS Sonoma.app” or “Install macOS Sequoia.app”) is mandatory. However, attempting to download these installers through the Mac App Store often initiates an automatic upgrade prompt or downloads a truncated 20MB stub installer that requires continuous internet access.
macOS includes a native, direct-to-Apple-CDN command-line tool designed for system administrators: softwareupdate –fetch-full-installer. This command downloads the complete 12GB+ installer package directly from Apple’s software distribution servers and packages it as an official application inside your /Applications directory. This guide explains how to list available installer versions and automate full downloads in macOS Terminal.
Locating Available Full Installer Versions
Before initiating a multi-gigabyte download, query Apple’s software catalog to see which operating system versions your Mac hardware is eligible to download:
softwareupdate --list-full-installers
Terminal queries Apple’s catalog servers and returns an enumerated list:
Finding available software
Software Update found the following full installers:
* Title: macOS Sequoia, Version: 15.0.1, Size: 13540231KiB, Build: 24A348
* Title: macOS Sonoma, Version: 14.7, Size: 13120984KiB, Build: 23H124
* Title: macOS Ventura, Version: 13.7, Size: 11984210KiB, Build: 22H123
Downloading the Latest macOS Installer
To download the latest compatible release version for your machine, execute the command without specifying a version flag:
softwareupdate --fetch-full-installer
Terminal will display download progress bars and package assembly phases:
Scanning for full installer
Installing: 12.5%... 45.0%... 89.2%... 100.0%
Install finished successfully
Once complete, the full application (e.g. Install macOS Sequoia.app) is deposited directly in /Applications/.
Downloading Specific Older macOS Releases
If you require a specific prior version (for enterprise compatibility or bootable drive creation), pass the --full-installer-version flag followed by the exact version string:
softwareupdate --fetch-full-installer --full-installer-version 14.7
Creating a Bootable USB Installer
Once the full installer is downloaded into /Applications, use the embedded createinstallmedia tool to construct a bootable USB drive in one terminal command:
sudo /Applications/Install\ macOS\ Sonoma.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB
Command Options Summary
| Command Syntax | Function | Prerequisites |
|---|---|---|
softwareupdate --list-full-installers |
Queries eligible OS installer builds from Apple servers | Active internet connection |
softwareupdate --fetch-full-installer |
Downloads latest compatible major macOS installer | ~15GB free disk space |
softwareupdate --fetch-full-installer --full-installer-version <X.Y.Z> |
Downloads targeted legacy macOS release | Hardware must be compatible with target OS |
Troubleshooting Download Errors
- Update Not Found / Version Ineligible: Apple’s catalog servers block downloads of macOS versions that your physical Mac hardware does not support. For instance, Apple Silicon M3 Macs cannot download macOS Monterey (12.x).
- Stalled Downloads: If a download stalls, cancel with Ctrl + C and clear temporary cache files from
/Library/Updates/before retrying.