How to Create a Bootable USB Drive for macOS - Full Tutorial

Creating a bootable USB drive for macOS can be a lifesaver on many occasions. Whether you're looking to install a fresh copy of macOS on your Mac, trying to install macOS on multiple Macs without downloading the installer each time, or dealing with boot problems on your Mac, a bootable USB drive for macOS can be incredibly useful. In this tutorial, we're going to walk you through creating one.

Prerequisites

Before proceeding, you need to gather few things:

- A USB drive. You need a drive with at least 12GB of available storage. All data on the USB drive will be erased during this process.

- A Mac. You can't create a MacOS bootable drive from a Windows PC.

- A copy of the macOS Installer. You can download this from the App Store.

Step 1: Download macOS Installer

The first step in creating a bootable USB drive for macOS is downloading macOS.

- Click on the App Store icon located in the Dock.

- Go to the search bar at the top right corner of the App Store. Next, start typing 'macOS'.

- Click on the macOS version of your choice.

- Click 'Download' button.

Please note, you may have to sign in with your Apple ID to start the download, and the download can take quite a while depending on internet connectivity.

Step 2: Prepare your USB drive

Next, you need to format your USB drive

- Connect the USB drive to your computer.

- Open Disk Utility (you can find it by typing 'Disk Utility' in the Spotlight).

- Choose the USB drive in the side bar.

- Click 'Erase'.

- Name the drive, select 'Mac OS Extended (Journaled)' for Format.

- Then click 'Erase' again.

Please remember, this will delete all data on your USB drive, so make sure you have backed up anything important.

Step 3: Create the Bootable USB Drive

Now you're ready to create your bootable USB drive for macOS.

- Open Terminal (you can do this by typing 'Terminal' in the Spotlight).

- Once Terminal is open, you need to enter the "createinstallmedia" command.

This is where things can get a little tricky as the command varies slightly depending upon which version of macOS you're downloading.

Let's assume you're creating a bootable drive for macOS Mojave. The command you would type is "sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/DiskName --applicationpath /Applications/Install\ macOS\ Mojave.app". Replace 'DiskName' with the name of your USB drive.

Once you’ve typed the command, hit Enter. You’ll then have to enter your Mac’s login password. After that, you just have to wait for the process to complete.

Step 4: Using Your Bootable USB Drive

If you ever need to use the bootable USB drive (for example, to reinstall macOS), simply insert the drive into your Mac, restart the computer while holding the Option key until you see the boot selection window, and choose the USB drive.

Congratulations! You have successfully created a bootable USB drive for macOS and you are now equipped to troubleshoot any macOS issues that may arise or to install macOS on as many computers as you like.