Are you looking to install or upgrade the operating system on your Mac? Creating a bootable installer USB can be a convenient and efficient way to accomplish this task. Whether you want to perform a clean install of macOS or have a backup installer handy, a bootable USB can be a lifesaver.
Why use a bootable installer USB?
One of the main advantages of using a bootable installer USB is that it allows you to install macOS on multiple computers without downloading the operating system multiple times. Additionally, having a bootable installer USB can be useful in case your Mac encounters any issues and you need to reinstall macOS quickly and easily.
In this step-by-step guide, we will walk you through the process of creating a bootable installer USB for your Mac.
Step 1: Check the system requirements
Before you begin, make sure your Mac meets the system requirements for the version of macOS you want to install. Visit the Apple Support website to find the system requirements for the latest version of macOS. It’s important to note that the process of creating a bootable installer USB may vary slightly depending on the version of macOS you are using.
Step 2: Download macOS installer
Next, you’ll need to download the macOS installer from the Mac App Store. Simply search for the version of macOS you want to install, such as macOS Catalina or macOS Big Sur, and click the “Download” button. The installer will be saved in your Applications folder once the download is complete.
Step 3: Prepare the USB drive
Now, you’ll need to prepare the USB drive to be used as a bootable installer. Connect a USB drive with at least 16GB of storage to your Mac. Open the Disk Utility application, select the USB drive from the left sidebar, and click on the “Erase” tab. Choose “Mac OS Extended (Journaled)” as the format, give the drive a name, and click “Erase” to format the drive.
Step 4: Create the bootable installer
To create the bootable installer, open Terminal from the Utilities folder in the Applications folder. Type the command “sudo /Applications/Install\ macOS\ [version].app/Contents/Resources/createinstallmedia –volume /Volumes/[USB drive name]” in Terminal, replacing “[version]” with the name of the macOS installer you downloaded and “[USB drive name]” with the name of your USB drive.
Step 5: Use the bootable installer
Once the bootable installer has been created, you can use it to install macOS on your Mac. Simply restart your Mac and hold down the Option key while it’s booting up. Select the USB drive from the list of startup disks, and follow the on-screen instructions to install macOS.
By following these steps, you’ll have a bootable installer USB ready to use whenever you need to install or upgrade macOS on your Mac. It’s a handy tool that can save you time and hassle in the long run.
Select and Download the macOS Installer
In order to create a bootable installer USB for your Mac, you will need to have the macOS installer file downloaded onto your computer.
Step 1: Check System Requirements
Before selecting and downloading the macOS installer, make sure your Mac meets the system requirements for the version of macOS you want to install. You can find the system requirements on the Apple website or by checking the documentation that came with your Mac.
Step 2: Visit the Apple Website
Go to the Apple website and navigate to the Downloads section. Look for the section related to macOS and find the version you want to download.
Step 3: Download the Installer
Once you have identified the correct version of macOS, click on the download link to start the download. The installer file is usually quite large, so be prepared for a longer download time if you have a slow internet connection.
| Version | Release Date |
|---|---|
| macOS Catalina | October 2019 |
| macOS Mojave | September 2018 |
| macOS High Sierra | September 2017 |
Make sure to save the installer file in a location that is easily accessible, as you will need it later in the process of creating the bootable installer USB.
Prepare the USB Drive
Before creating a bootable installer USB for your Mac, you need to prepare a USB drive that will serve as the installation media. Follow these steps to prepare the USB drive:
Step 1: Check Compatibility
Make sure that the USB drive you intend to use is compatible with your Mac. Check the technical specifications of your Mac model to see what type of USB drives it supports. Ideally, the USB drive should be USB 3.0 or later for faster data transfer speeds.
Step 2: Format the USB Drive
Formatting the USB drive will erase any existing data on it, so make sure to back up any important files before proceeding. To format the USB drive, follow these steps:
- Connect the USB drive to your Mac.
- Open the “Disk Utility” application, which you can find in the “Utilities” folder within the “Applications” folder.
- Select the USB drive from the list of available drives on the left-hand side of the Disk Utility window.
- Click on the “Erase” tab.
- Choose a suitable format for the USB drive, such as “Mac OS Extended (Journaled)”.
- Give the USB drive a name and click on the “Erase” button to begin the formatting process.
Step 3: Create a Partition
After formatting the USB drive, you will need to create a partition on it. Follow these steps to create a partition:
- Select the USB drive from the list of available drives in the Disk Utility window.
- Click on the “Partition” tab.
- Click on the “+” button to add a partition.
- Specify the size of the partition, keeping in mind that it needs to be large enough to accommodate the macOS installer files.
- Choose a suitable format for the partition, such as “Mac OS Extended (Journaled)”.
- Give the partition a name.
- Click on the “Apply” button to create the partition.
Once you have prepared the USB drive by formatting it and creating a partition, you are ready to proceed with creating the bootable installer USB for your Mac.
Create a Bootable USB Drive with Terminal
If you prefer using Terminal, you can create a bootable USB drive for your Mac using a few simple commands. Follow the steps below:
Step 1: Check the USB Drive Name
First, insert the USB drive into your Mac and open the Terminal app.
Type in the following command to list all the connected storage devices:
diskutil list
Look for your USB drive in the list – it will be identified by its size and type.
Step 2: Format the USB Drive
Once you have identified the USB drive, you need to format it to work with macOS.
Type the command below, but replace /dev/diskX with the identifier of your USB drive from Step 1:
diskutil eraseDisk MS-DOS "USB" /dev/diskX
Be careful when entering the command, as it will erase all data on the USB drive.
Step 3: Create the Bootable Installer
Now, you are ready to create the bootable USB installer for your Mac.
First, download the macOS installer from the App Store or Apple’s website, but do not run the installer.
Next, use the following command to create the bootable installer:
sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/USB
Replace /Applications/Install\ macOS\ Catalina.app with the path to the macOS installer you downloaded, and /Volumes/USB with the name of your formatted USB drive.
Enter your admin password when prompted, and then wait for the process to finish.
Note: The name of the macOS installer and the version may vary depending on the version you are using.
Once the bootable USB drive is created, you can use it to install macOS on any compatible Mac by restarting the computer and holding the Option key during startup. Select the USB drive from the menu and proceed with the installation.
That’s it! You have successfully created a bootable USB drive for your Mac using Terminal. This method provides a quick and efficient way to install or upgrade macOS on multiple Macs, or if you prefer using the command line interface.
Boot from the USB Drive and Install macOS
Once you have created a bootable installer USB for macOS, you can now proceed with the installation process on your Mac.
Step 1: Safely eject any other external drives
Before proceeding with the installation, it is recommended to safely eject any other external drives connected to your Mac. This is to avoid any confusion during the boot process.
Step 2: Restart your Mac and access the boot menu
Restart your Mac and immediately press and hold the Option key on your keyboard. This will bring up the boot menu, where you can select the USB drive as the boot device.
Note: Depending on your Mac model, the boot menu key may be different. You can refer to the documentation or search online for the specific key combination for your Mac model.
Step 3: Select the USB drive as the boot device
Once you have entered the boot menu, you should see a list of available boot devices. Use the arrow keys to select the USB drive and press Enter to boot from it.
Note: The USB drive might be labeled as “Install macOS” or something similar.
Step 4: Start the macOS installation
After selecting the USB drive as the boot device, your Mac will start booting from it. You will see the Apple logo and a progress bar indicating the installation process. This may take a while, so be patient.
During the installation process, your Mac may restart multiple times. This is normal, so avoid interrupting the process.
Step 5: Follow the on-screen instructions
Once the installation is complete, the macOS setup wizard will appear on the screen. Follow the on-screen instructions to set up your macOS, including selecting your language, agreeing to the terms and conditions, and setting up your user account.
Make sure to connect to a reliable internet connection during the setup process to download any necessary updates or software.
Finally, you will be taken to the macOS desktop, and you can start enjoying your newly installed operating system!
Remember to properly eject the USB drive before removing it from your Mac.
What is a bootable installer USB for Mac?
A bootable installer USB for Mac is a USB drive that contains the operating system installer for a Mac computer. It allows you to boot your Mac from the USB drive and install or reinstall the operating system.
Why would I need to create a bootable installer USB for Mac?
There are several reasons why you might need to create a bootable installer USB for Mac. It can be useful for reinstalling the operating system, troubleshooting issues, or creating a portable installer for multiple Mac computers.
What do I need to create a bootable installer USB for Mac?
To create a bootable installer USB for Mac, you will need a USB drive with at least 12 GB of storage, a Mac computer, and a copy of the macOS installer from the App Store.
