Creating a bootable macOS Catalina USB install drive is an effective way to generate a clean installation of macOS on your Mac. This hands-on tutorial will work with both the macOS Catalina developer beta, the macOS Catalina public beta, and the final version of macOS Catalina scheduled to launch later this fall. Follow our easy-to-use step-by-step video tutorial for the details.
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Before beginning you’ll need to acquire a USB flash drive. In the age of USB-C, it’s preferable that you use a USB flash drive with a USB-C connection if possible.
You’ll want a USB drive with at least 8GB of storage, but having more storage is never a bad thing. I recommend this SanDisk Ultra Dual Drive USB Type-C Flash Drive. It’s affordable, and comes with both a USB-C connection and a traditional USB-A connection. This is the drive that I’ve been using and my experience with it has been great.
The drive comes in 16, 32, 64, 128, and 256GB storage varieties. If you want a drive with extra storage, then it makes sense to opt for a higher tier, but if you just plan on using it as a USB installer, then 16GB should be plenty.
Make sure that there’s nothing contained on the drive that you need, because this process will completely delete the contents of the drive.
macOS Catalina USB installer video tutorial
Thanks to CleanMyMac X for sponsoring this video. Try CleanMyMac X for macOS.
How to create a bootable macOS Catalina 10.15 USB install drive
Step 1: Download macOS Catalina. After Catalina 10.15 launches later this fall, you’ll be able to download it directly from the Mac App Store. Until then, you can download the macOS Catalina developer beta from Apple’s developer portal, or download the macOS Catalina public beta via Apple’s public beta website.
Step 2: After successfully downloading macOS Catalina, the installer will auto-launch. Close the installer.
Step 3: Open Finder → Applications and right-click on Install macOS Catalina Beta and choose Show Package Contents.
Step 4: Open Contents → Resources.
Step 5: Launch a Terminal window via Applications → Utilities → Terminal.
Step 6: In the Terminal window type
sudo followed by a space.
Step 7: Drag createinstallmedia to the Terminal window from the Finder location noted in Step 4.
Step 8: Type
--volume followed by a space.
Step 9: Open Finder → Go → Go To Folder…
Step 10: In the ‘Go to the folder’ box type /Volumes and click Go.
Step 11: Connect your USB drive to your Mac, and it should appear in the Finder window.
Step 12: Drag the USB flash drive volume into the Terminal window.
Step 13: Press Return on the keyboard to submit the full command and enter your password when prompted.
Step 14: Type a ‘y’ to continue when prompted, and press return on the keyboard.
Step 15: The install process will commence by erasing the contents of your USB drive, and afterwards, copying the installer files to the drive. The entire process will take a few minutes to complete, so you’ll need to exercise patience as the install process proceeds.
Having a USB installer available can make installing a fresh copy of macOS even easier. For instance, you can boot directly from the USB drive by holding the Option (⌥) key on your Mac while booting with the drive connected.
You can use this tutorial on either the developer beta, public beta, or the final version of macOS Catalina that’s scheduled to release later this fall. Keep in mind that on newer T2-enabled Macs, you may have to enable booting from external storage via macOS Recovery. We’ll address that in a future tutorial.
Do you like to have a USB installer on hand, or do you prefer to stick to other methods for reinstalling macOS? Sound off in the comments below with your thoughts, and don’t forget to read and watch our overview of the Top macOS Catalina features.