To boot macOS from a USB on an M1 or M2 Mac, first ensure the USB installer is compatible with Apple Silicon. 1. Create a bootable installer using another Mac and the createinstallmedia command in Terminal. 2. Format the USB drive as Mac OS Extended (Journaled) with a GUID partition scheme and at least 16GB storage. 3. Shut down your Mac, plug in the USB, then press and hold the power button to access startup options. 4. If the USB doesn’t appear, check Secure Virtual Memory settings, try a different port or cable, or use Recovery Mode to troubleshoot. 5. Recreate the installer if necessary.

Booting from a USB to install macOS on an M1 or M2 Mac isn’t quite the same as on Intel-based models. Since Apple Silicon Macs don’t use a traditional BIOS or boot menu, you’ll need to adjust your approach a bit.

Set Up Your Mac for Booting from USB

Before trying to boot from a USB drive, make sure your Mac is ready. First, ensure that the USB installer is compatible with Apple Silicon — it needs to be a properly created macOS installer for ARM architecture (not Intel). Most macOS versions from Big Sur onward support this.

Then, shut down your Mac completely. Once off, plug in your USB drive into a compatible port (USB-C for most M1/M2 Macs). If you're using a dongle or hub, double-check that it’s powered and compatible — some third-party hubs may not power the drive correctly during boot.

Now, press and hold the power button until you see the startup options appear. You should see both your installed system and a removable disk option (your USB drive).

Create a Bootable macOS Installer for Apple Silicon

Creating a working USB installer is crucial. Use another Mac to download the macOS installer from the App Store — make sure it's one that supports Apple Silicon (like Ventura, Sonoma, or Sequoia). Once downloaded, open Terminal and use the createinstallmedia command.

Here’s a basic example:

sudo /Applications/Install\ macOS\ Ventura.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB

Replace “Ventura” and “MyUSB” with the actual installer app name and your USB volume name.

Important: Don’t skip formatting the USB drive first. It should be formatted as Mac OS Extended (Journaled) and use a GUID partition scheme. Also, make sure the USB stick has at least 16GB of storage — 32GB is safer if you’re installing multiple tools or packages alongside the OS.

What to Do If the USB Doesn’t Show Up

Sometimes the USB won’t show up in the startup manager. Here are a few common fixes:

• Check Secure Virtual Memory settings: Go to System Settings > Startup Disk > click the lock icon and enable "Allow booting from external media." This setting might be turned off by default.
• Try a different port or cable: Some USB-C ports or cables may not work well for booting. Try switching ports or using a known-good cable.
• Use Recovery Mode to troubleshoot: Hold the power button until the startup options appear, then choose Options to enter Recovery. From there, you can check disk utilities or re-enable external booting.

If none of those work, try recreating the installer — sometimes even a small error during creation can prevent it from being recognized.

That’s basically all you need to know to boot from USB on an M1 or M2 Mac. It’s not overly complicated once you’ve got the right installer and hardware setup. Just remember that Apple Silicon handles things differently, so always double-check compatibility and settings before you start.

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