How To Install macOS From USB

Lee Stanton December 1, 2022

Having a backup of your macOS is a great way to be proactive in case you have issues with your Mac. By having a backup of the operating system, you can easily restore your Mac’s OS or install it on several different devices. Taking the time now to create a bootable installer can save you lots of headaches if you require one in the future.

In this article, we’ll cover how to install macOS from a USB using several methods.

Install macOS From USB in Recovery Mode

If you’re having issues with your Mac, one solution is to reinstall the macOS using a bootable USB. Using this method can save you from the headaches of trying to diagnose the problem. This method is straightforward. Here’s how you do it:

Shut down your Mac.
Plug in the bootable USB.
Start your Mac and hold down the “Option/Alt” key to place it in recovery mode.
When your Mac displays the Startup Manager, click on the external drive USB that you plugged in.
Select “Install macOS” and hit “Continue.”
The OS will install from your bootable USB.
Once the process finishes, your Mac will automatically reboot.

Install macOS From USB Disk Utility

Another way to install macOS from a USB is to use the Disk Utility method. Please note that using this method will erase everything currently on your Mac’s hard drive. If you’re having issues with your Mac booting properly, this should solve the problem. Here’s what you’ll need to do:

Turn off your Mac.
Insert your bootable USB.
Hold down the “Option” key and restart your Mac.
After it restarts, select the USB and choose “Disk Utility.”
Tap your Mac’s main hard drive, click “First Aid” and then “Erase.”
From the popup window, for “Format,” select “OS X Extended (Journaled)” and hit “Erase.” This will erase your main drive.
Once completed, close the Disc Utility window and choose “Install OS X.”
Select your main drive to install the macOS from your USB.
Once the process ends, your Mac will reboot and your new OS will be operating.

Install macOS From USB Without Internet

Installing macOS with a bootable USB doesn’t require having an internet connection. However, you’ll first need to create the backup. Having a USB that you can boot from and reinstall your macOS is well worth the time it takes to make one. If you have issues with your Mac, this handy device can save a lot of time. You’ll need to first download an app and have a USB drive with a minimum of 8GB of space. To create one, follow the instructions below:

Download Disk Maker to your Mac. Choose which OS version you’d like to use.
Download the macOS you want for your bootable USB and save it in your Applications folder.
Launch the Disk Maker installer and copy the app to your Applications folder.
Disk Maker will detect the downloaded OS. Click “Use this Copy.”
Plug in your USB drive. From the popup window, select “8 GB USB Thumb Drive.”
You’ll see a list of all of the drives on your Mac. Pick the one you would like to use as your macOS USB installer.
Tap “Erase and Create macOS USB Disk.”
The creation process could take some time. Once it’s completed the process, unmount the USB.
Keep the USB drive in a safe place. You’ll need it if you ever have to reinstall your macOS.

Additional FAQs

I don’t have a bootable USB drive. Is there anything else I can do to reinstall my macOS?

Yes. Fortunately, you have a few other options to reinstall your OS. Your Mac has a built-in recovery system that you can use. Here are your options:

1. Turn off your computer.

2. Hold down “Command + Option + Alt + R” and press the power button.

3. You’ll see the words “Starting Internet Recovery.”

4. A progress bar will appear on the screen. Wait for all the processes to complete.

5. Your Mac will automatically reboot.

I can’t get my Mac to boot in Recovery Mode. What should I do?

Sometimes your Mac might give you problems when trying to boot in Recovery Mode. Your recovery partition could be corrupt or the startup volume has been erased. If you encounter this problem, try this:

1. Restart your computer.

2. Go to “Applications” and then “Utilities.”

3. Locate and launch the “Terminal” app.

4. Type “diskutil list”. Hit the enter key.

5. You’ll see a list of all of your Mac’s drives and partitions.

If you don’t see either “Apple_Boot Recovery HD” or “APFS Volume Recovery,” then you’re Mac doesn’t have the proper recovery partition. You may be able to restore this by following the steps below:

1. Restart your computer while holding down the “Command + Option + P + R” keys.

2. Release them after hearing the second chime.

3. Your Mac will automatically reboot.

4. Navigate to “Applications” and then to “Utilities.”

5. Type in “diskutil list” and hit Enter.

6. Check to see if you now have either “APFS Volume Recovery” or “Apple_Boot Recovery HD.”

If you now have them, you should be able to boot your Mac in Recovery Mode.

Can I restore my Mac from a backup?

If you’re having issues with your macOS, sometimes it’s a good idea to try and restore it to an earlier time. You may have downloaded an app or plugin that has caused an issue, so restoring your Mac to an earlier state could solve the problem. Periodically creating a restore point is a great way to be proactive and protect yourself from bigger issues that could arise. Here’s how to do it:

1. Power on your computer and hold down the “Command + R” keys.

2. Hold them down until you see the Apple logo appear on the screen.

3. The Utilities window will open. Select “Restore from Time Backup” and click on “Continue.”

4. Tap “Continue” again.

5. Choose a backup date from before you started having problems and hit “Continue.”

Install macOS From a USB Drive Solved

It’s a good idea to have a bootable USB drive if you ever have issues with your Mac’s OS. Having an alternate way to boot your Mac can save you from the troubles of trying to diagnose issues. To reinstall macOS, you don’t need to be connected to the internet and you can do so in either Recovery Mode or by using Disk Utility.

Have you had to reinstall macOS from a USB? Did you follow the methods outlined in this article? Let us know in the comments section below.