Paul Morris on October 7, 2019, 11:08 pm

How To Create macOS Catalina Bootable USB Flash Drive Installer

Here’s how to create macOS Catalina 10.15 bootable USB flash drive installer for a clean install on your Mac. With macOS Catalina being Apple’s latest software release, it stands to reason that there is going to be a big interest in it.

This process will show you how to be in a position to always have an executable and installable version of Catalina with you.

Let’s not waste any additional time talking about the ins and outs and let’s just dive right into the process.

Step 1: First of all, you are going to need to have a USB drive with at least 8GB of storage as a minimum. It doesn’t need to be a specific make or model however if you need a recommendation, we will recommend getting the SanDisk dual USB A+USB C drive in any capacity from here. Ensure that the drive is inserted into the Mac.

Step 2: You will also need to have the macOS Catalina installation file downloaded to your machine and sitting in /Applications folder waiting for you. If you haven’t yet, grab it now: Download: macOS Catalina 10.15 Final DMG / ISO Released, Update Now.

Step 3: Now, launch Finder and select the Applications option from the left sidebar.

Step 4: Find the Install macOS Catalina file in the Applications folder. Right-click on it an select Show Package Contents.

Step 5: Navigate to Contents > Resources and then locate the createinstallmedia file.

Step 6: Keep that Finder window open and launch Terminal on the Mac. Type sudo, hit the space bar, and then drag and drop the createinstallmedia file from the Finder window into Terminal. You will notice that it places text into the Terminal window.

Step 7: After the text that it automatically populates, type –volume, hit the space bar so you should end up with “sudo [auto-populated string] –volume “

Step 8: Now, go back into the Finder window, select connected drives and locate your USB drive. Click on this and drag and drop it into the Terminal window app. You will now have a full command pre-populated.

Step 9: Press Return on the keyboard and enter the password for the machine. Then type Y and press Return to continue when prompted. The Terminal will now show that the disk is being erased and prepared. It will then start copying data over to the disk to leave you with a fully bootable USB drive running macOS Catalina.

And that’s about it. You should now have a bootable USB drive of macOS Catalina installer. Next step is to do a clean install of your Mac using this drive, instructions for which can be found over at: Clean Install macOS 10.15 Catalina On Mac Via USB Drive, Here’s How [Guide].