Applet just release macOS 10.15 Catalina, although I can upgrade OS, but I love to clean install macOS. It's good time to clear junk file or application that I no need. Basically you can use command line to make an USB bootable, but it's not easy for user level. Here is simple way to make a USB bootable without any command line.

Download Catalina

  1. Open App store
  2. Fine out "macos catalina"
  3. Click at "Get" button to download

After downloaded, you should see above screen. leave it.

at Launchpad. you should see an application name "Install MacOS Catalina"

Download macdaddy's Install Disk Creator

I use the application to create USB bootable. Easy to use, just download from https://macdaddy.io/install-disk-creator/. After download, open the apps you should see screen as below.

Easy to use, just

  1. Attach your USB to MacOS then choose USB as volume disk target
  2. Choose a Mac Installer. Normally the software should auto select if you have download Catalina
  3. Make sure you have no any important data in USB. It's will erase anything.
  4. Click "Create Installer"

It will copy file around 9.1 GB to USB. Just wait until finish, you should see successful screen. Let's clean install :)