How Can I Install macOS from a USB Drive?
How Can I Install macOS from a USB Drive?
1 Answer

So, you’re thinking about installing macOS from a USB drive? Let’s make it happen! Here’s what you need and how to do it:
What You’ll Need:
- A USB drive with at least 16GB capacity.
- The macOS installer you’ve downloaded from the App Store.
- Your trusty Mac.
Steps to Get There:
Snag the macOS Installer:
Head over to the App Store and grab the installer for the macOS version you want. It’ll land right in your Applications folder. Easy peasy!
Prep Your USB Drive:
- Stick the USB into your Mac.
- Open Disk Utility by going to Applications > Utilities > Disk Utility.
- From the list on the left, click on your USB drive.
- Choose “Erase,” pick “Mac OS Extended (Journaled)” format, and give it a name like “macOSInstaller.”
- Hit “Erase” and watch the magic happen.
Make That USB Bootable:
- Fire up Terminal (Applications > Utilities > Terminal).
- Punch in this command, swapping “Mojave” for whichever macOS version you’re dealing with:
sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/macOSInstaller
Hit Enter, pop in your admin password, and let the command take care of business.
Time to Install macOS:
- Restart your Mac. While it’s booting, hold down the Option key.
- When the Startup Manager pops up, use the arrow keys to pick your bootable USB drive and hit Enter.
- You’ll now be in the macOS Utilities window. Pick “Install macOS” and just roll with the instructions on the screen.
- Choose where you want the macOS installed—your main hard drive, maybe? Then follow along till it’s done.
Troubleshooting Tidbits:
- Double-check that your Mac is good to go with the macOS version.
- If your Mac doesn’t recognize the USB, try switching USB ports or stash it in a different USB drive.
- Ensure your USB drive’s large enough and correctly formatted.
Follow these steps, and you’ll be running macOS from your USB drive like a champ. If hiccups persist, Apple’s support page or forum folks are always there to lend a hand.