How To Create a Bootable macOS Catalina USB Drive.
Making a bootable USB installer for the latest macOS Catalina helps in many ways. One of the reasons you might want to do this is because it allows you to perform a completely clean install of the update on your Mac. Other areas where you can use a bootable macOS installer is when you have multiple Macs and want to install the same update on all of them.
With one USB installer, you don’t have to download the update to each of your Macs. The same USB drive can be used to update all your Macs to the latest version available on it.
All you need is a USB stick with at least 8GB of storage. Then you can use an app or several commands in the Terminal app on your Mac to turn your drive into a macOS installer. We’ll show you how to do this below.
Download the macOS Catalina update to your Mac
The first thing you need to do is download the entire update to your Mac. Then you will place this downloaded file as an installer on your USB stick.
- Launch the Mac App Store, find and click macOS Catalina.
- Click “Download” on the next screen to download the update.
- Sit back, relax, and wait for the update to finish downloading to your Mac.
This is a fairly large update and will take about an hour to fully download to your computer. The download time also depends on your internet speed.
Make sure you don’t continue with the installation that opens after downloading the update.
Create the macOS Catalina USB Installer using Disk Creator
One of the easiest ways to create a bootable installer for any macOS update, including Catalina, is to use the Disk Creator app. This is a simple program that lets you download an update and then create an installer based on it.
It has a graphical user interface, so you don’t have to mess with any commands. Also, keep in mind that the app will erase all existing data stored on your USB drive. Make sure to back up important files before proceeding.
- Go to the Disk Creator website and download the package to your Mac. Extract the files from the downloaded archive and run the main application file.
- There are only a few options in the main interface of the application. The first thing you need to configure is the destination of the installer. Click the dropdown at the top and select your USB drive.
- Then click the Select macOS Installer button to select the macOS Catalina update downloaded to your Mac.
- Once you have provided both the USB drive and the Catalina file to the application, click the Create Installer button at the bottom of the application to begin the process.
- Wait a few minutes for the USB installer to be created. When everything is ready, a success message will appear on the screen.
Your USB installer for installing macOS Catalina is now complete. Connect it to any of your Mac computers that need to update to this version of macOS.
Use Terminal to create a macOS USB installer
If you are a user who distrusts third-party applications, especially when installing entire operating systems, you don’t need to use Disk Creator to create an installer.
You can use the Terminal app on your Mac to create a USB installer, and that too with just a few commands. Again, all you need is an 8GB or larger USB drive and a macOS Catalina update file.
- Open a Terminal app on your Mac, type sudo, press space, but don’t press Enter yet.
- Launch a Finder window, open the Applications folder, find the update for macOS Catalina, right-click the file and select Show Package Contents.
- Open the Contents folder and then Resources. Find a file named createinstallmedia and drag it into the Terminal window. It will fill the path of renewal.
- In a terminal window, press the spacebar, enter –volume, press the spacebar, and drag your USB device from Finder into the terminal window. This will be the full path to your USB drive.
- Press Enter and since this is a sudo command, you will be prompted for a password. Enter your password and continue.
- Press the y key on your keyboard and press Enter to erase the disk and install the Catalina installer on it.
It will start erasing data from the USB drive to then turn it into a bootable installer. Wait for it to end. Just keep an eye on the Terminal window and you’ll know when it finishes creating the installer.
How to use the macOS Catalina USB installer
Once the USB installer is created and you have as much fun installing the update as we do, you just need to follow a few steps to get your Mac to boot from the installer.
You can use the newly created installer in two ways.
Use system settings to boot from USB installer
The first method is to change the startup option so that your Mac boots from the USB installer instead of the current boot drive.
- Click the Apple logo and choose System Preferences.
- Select “Startup Disk”, select your USB drive and click “Restart”.
Your Mac will reboot and boot from the Catalina installer, allowing you to perform a full clean install of the operating system.
Boot directly from USB installer
This method does not require changing any startup parameters to use the installer.
- Shut down your Mac.
- Turn on your Mac and hold down the Option key.
- Select a USB installer from the list and proceed with the installation.
Then you follow the standard macOS installation steps to upgrade your Mac computers to this new version of the operating system.