How to make Catalina bootable USB Disk

Sometimes, things happen and your Mac cannot reboot for some reason. So, I have to make a bootable disk in order to re-install macOS on my Macbook Air.

First, we need to download macOS installer. Since my other Mac already have Catalina installed so I cannot download the installer app from the AppStore. we’ll need to download the macOS Catalina Patcher, a small app that let you easily download Catalina installer (full instruction can be found here).

After you got a full copy of Installer image, you can use Install Disk Creator, an app for building USB bootable from image by just drag and drop (In fact, you can use macOS Catalina Patcher to create bootable disk but I didn’t successfully create the bootable USB-C disk from this app).

Finally, insert USB to your macOS. Press the Power button to turn on your Mac, hen you hear the startup chime, press and hold the Option key.