How to boot macOS from a USB drive and what is the purpose of doing so

The macOS operating system is characterized by being extremely stable and secure. So, on very rare occasions, you will need to completely restore it and reinstall macOS from scratch. Given the latest features, macOS can be reinstalled without the need for a USB drive or thumb drive. However, if you need it for a specific exception, or if you prefer to do it using this method, we will help you. Boot macOS from USB Drive Now create an installation USB drive with the version of macOS that matches your Mac.

Reasons to Boot Your Mac from a USB Drive

There are several reasons why you may need to boot your Mac from a USB port. Needless to say, it doesn’t have to be a USB flash drive; it’s also possible to do it from an external hard drive. However, keep in mind that it will need to be completely formatted. So, if you have any information inside the USB drive, it will be better to save it before booting the Mac from it. Here are some reasons why you might want to boot macOS from a USB drive:

• Clean install of macOS: A clean install of macOS from a USB drive allows you to erase the internal hard drive and reinstall the operating system from scratch. This can be useful for removing residual files from improperly uninstalled applications and optimizing your computer’s performance.
• Problem resolution: If your Mac won’t boot properly from the internal hard drive, a bootable USB drive can help you access diagnostic and repair tools.
• Testing new versions: You can use a bootable USB drive to test macOS betas without compromising your main installation, allowing you to explore new features risk-free.
• Backup and Recovery: In the event of serious breakdowns, having a bootable USB key with macOS allows you to recover data or restore the system quickly and efficiently.

How to Create a macOS Installation USB Drive

Although you don’t need a bootable US to update or reinstall macOS, it can be useful if you want to install macOS on multiple Macs without downloading the installer every time or if there is an error while installing a compatible macOS from macOS Recovery. These steps are advanced, so we recommend following them only for experienced users who are familiar with entering commands in Terminal.

Download the macOS version

To download macOS, you’ll just need to go to the Mac App Store. Make sure you’re downloading macOS from a Mac with the latest version of OS X El Capitan or later. Also, make sure that Your Mac is compatible with the version of macOS you are downloading. You can check which version of macOS your Mac is using in System Preferences. Here are the download links:

Create the installation USB key

Once the installer is downloaded, make sure the** installer is in the “Applications”** folder. Check that the installer is named “Installer (version name)”, for example “Install macOS Sonoma”. It must be an application (.app) and not a disk image file (.dmg) or a package (.pkg).

1. Connect USB to Mac with minimum capacity of 32GB.
2. Open the Terminal application
3. In the terminal type or paste one of the following commands, adapting “MyVolume” to the name of your USB drive. After copying the text and changing the name of the USB drive, press the Enter key.

You may need to enter your login password from the Mac and confirm that you want to erase the USB drive by typing “Y” and pressing Enter. The Terminal will display the progress while the USB installation is erased and prepared. Once the Terminal indicates that the installer is ready, the USB drive will be renamed. At this point, you can exit the Terminal and eject the USB drive.

Start and power on your Mac from USB

Now it’s time to connect the USB to the Mac to turn it on from there. This way you can restore the Mac (remember to erase the hard drive first) or simply install the operating system on top. It will depend on your needs. Something that will determine how you proceed will be whether your Mac has an Intel processor or an Apple chip.

Boot your Intel Mac from USB

To boot an Intel Mac from a USB port, follow these steps:

1. Turn off your Mac.
2. Connect the USB you created.
3. Turn on your Mac and hold down the “Option” (⌥) key during startup.
4. Select the USB drive from the list of bootable devices that appears on the screen. Your Mac will boot from the USB, allowing you to install or repair macOS as needed.

Boot your Mac with Chip M from USB

The process for Macs with the Apple Silicon M chip is slightly different:

1. Turn off your Mac.
2. Connect the USB you created.
3. Turn on your Mac and hold down the power button (Touch ID) until the Startup Options window appears.
4. Select the USB drive from the list of startup devices that appears. Your Mac will boot from the USB drive, allowing you to access the most basic tools like erasing the hard drive from Disk Utilities or reinstalling macOS.

Erase hard drive before installation

To perform a clean install of macOS, You must first erase your Mac’s hard drive. Once you have booted the Mac from the USB drive, you will have a window with different tools:

1. Select “Disk Utility” and click on the Macintosh HD disk
2. Click “Erase” at the top of the Disk Utility window.
3. Choose either “APFS” or “Mac OS Plus Journaled” format depending on your needs. If you see “APFS” as an option, choose that first. If you only see “Journaled Mac OS Plus,” your Mac doesn’t support APFS.
4. Rename the disk, for example “Macintosh HD”.

Once the erasing process is complete, Close Disk Utility to return to the Tools screen. Now it’s time to install macOS. Follow the on-screen instructions to complete the installation on the disk you just erased. In some twenty minutes Approximately, your Mac will be completely formatted and macOS will be installed again.

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