Make a Bootable macOS USB Installer with createinstallmedia
Turn any 16 GB+ USB stick into a bootable macOS installer using Apple's built-in createinstallmedia tool.
Run sudo /Applications/Install\ macOS\ [Version].app/Contents/Resources/createinstallmedia --volume /Volumes/YourUSB to create a bootable installer.
01Command
Command
$ sudo /Applications/Install\ macOS\ Sonoma.app/Contents/Resources/createinstallmedia --volume /Volumes/Installer02What it does
The full macOS installer app downloaded from Apple ships with createinstallmedia, Apple's official tool for writing that installer onto a USB drive as a bootable volume. Once made, you hold the power button (Apple silicon) or Option (Intel) at startup to boot from it and install, reinstall, or repair macOS without an internet connection. It is the standard way to revive a Mac that will not start or to set up several machines from one download.
03Risk
!Warning: createinstallmedia erases the target USB drive completely — copy off anything you need first. If Terminal reports the volume is not suitable, reformat the stick in Disk Utility as Mac OS Extended (Journaled) with a GUID partition map.
04Undo
✓No undo needed — this command does not change persistent state.
05Sources
- How to create a bootable installer for macOSEvidence: Apple's step-by-step official guide listing the exact createinstallmedia command for each macOS version and the 16 GB USB requirement.
Last verified: 2026-09-18 · Category: System & Settings