- If you have more than one Mac you want to upgrade to macOS 10.15 Catalina but don't want to waste so much bandwidth downloading it for each machine, one option is to create a bootable installer on.
- Step Three: Create macOS Catalina Bootable USB Installer in Windows on Terminal. The USB installer has now been formated, it’s time to create and copy the installer with a command on Terminal. For this purpose, open Spotlight and type Terminal.
An external drive that you can use as an installer for macOS Catalina is a handy thing to have. If you have multple Macs to upgrade, it’s a lot more efficient to plug in the USB installer drive and run the installer than to log into the App Store, download the 8.09GB OS installer, and then run it.
In this article I’ll go over the different ways you can create a bootable macOS Catalina installation drive. But before I give instructions on how to create the drive, I’ll go over the items you’ll need and how to get them.
Presumably because quite reasonably it would not make sense to install on top of a later version of the OS. However in this case I want to create a boot USB drive for an installation on another Mac. I am stuck in a chicken and egg situation where I need another machine running El Capitan or earlier to create and El Capitan boot installer. Currently, you can only create a bootable installer for macOS Big Sur, Catalina, Mojave, High Sierra, or El Capitan. If you want to go back to your previous macOS, here's how to downgrade macOS.
Get an external drive and maybe an adapter
The macOS Catalina installer software is over 8GB, so you need a USB external drive that can hold that much data. The drive can be a thumb drive, hard drive, or SSD.
If you have a 2015 or newer MacBook or a 2016 or newer MacBook Pro, you may need Apple’s $19 USB to USB-C adapter. This will allow you to connect a storage device that uses a USB type-A connector. If you don’t have an external drive and you have a USB-C Mac laptop, you could buy the SanDisk Ultra USB Type-C Flash Drive, which has a USB-C connector. You can get model number SDCZ450-016G-G46.
How to create a bootable macOS Catalina installer drive Put the macOS Catalina installer on an external USB thumb drive or hard drive and use it to install the operating system on a Mac. Turn on your Mac and continue to hold the power button until you see the startup options window, which shows your bootable volumes and a gear icon labled Options. Select the volume containing the bootable installer, then click Continue. When the macOS installer opens, follow the onscreen instructions. MacOS Catalina Patcher lets you install macOS Catalina on Mac computers that are no longer officially supported. It can help you create a bootable USB drive that can be used to install macOS Catalina on Mac computers older than mid 2012. Point to your Mac OS.dmg or.iso file by clicking the add button. After that TransMac will create bootable Mac OS USB within few minutes. Then you can insert it into your Mac, hold down the option key while turn on and boot your system with this USB. If you’re unable to use Internet Recovery Mode or create a bootable USB installer, you can still use a Mac OS X installation disc. These discs are available for OS X Snow Leopard, OS X Lion, and OS X Mountain Lion. If your Mac is from 2012 or earlier, there was an installation disc in the original box.
When creating the boot drive, the storage device is reformatted, so there’s no need to format the drive beforehand.
Get the macOS Catalina installer software
The macOS Catalina installer is available in the App Store. If you launch the App Store app, do a search for “Catalina.” Or, if you click this Catalina App Store link, it will take you to the Catalina App Store webpage, then click on the “View in the Mac App Store” button.
You can read the information to learn more about Catalina. When you’re ready to download the software, click the Download button. (If you’ve already downloaded the installer, the button will say Install instead of Get.)
Once the download is complete, the installer will launch automatically. But don’t continue with the installation. Instead, press Command-Q on your keyboard to quit the installer.
The Catalina installer app will be in your Applications folder, so you can go there and launch it later to upgrade your Mac to the new operating system.
Make a bootable installer drive: The quick way
I used a free app called Install Disk Creator to make the installation drive. Download Install Disk Creator by clicking on the link. When the download is done, you can move it over to your Applications folder. Then follow these steps to create your bootable macOS Catalina drive.
1. Connect your drive to your Mac.
2. Launch Install Disk Creator.
3. In the main window, you’ll see a pop-up menu under Select the volume to become the installer. Click on the menu and select your drive.
4. Under the pop-up menu, you’ll see Select the OS X installer. (macOS used to be called OS X.) If you have only the Catalina installer on your Mac, Install Disk Creator will automatically select it. If you have other macOS installers, you need to click on Select the OS X installer and select the Catalina installer.
5. When you’re ready, click Create installer. Your Mac may tell you that Install Disk Creator wants to make changes, and you need to enter your user name and password. After you do this, the app will take a few minutes to create the boot drive. A progress bar. appears at the bottom of the Install Disk Create window.
If you try to start the process and you get a failure message saying that the drive couldn’t be unmounted, try reformatting the drive first as ExFAT using Disk Utility. Then start the process over again.
Create Bootable Usb Mac Catalina
Macos Catalina Bootable Installer
When the app is done, the installer is ready to use.