Once the download finishes, the installer might try to launch automatically. Do not click "Continue" yet. If it opens, quit the installer from the menu bar. 4. Step 3: Install macOS onto the External Drive
Installing macOS on an external drive turns a $20 enclosure into a multi-booting powerhouse. Whether you are a developer testing the next beta or a video editor needing a scratch disk OS, this is the safest way to push your Mac to its limits. install mac os on external drive
If you want to install macOS on an external drive using another Mac: Once the download finishes, the installer might try
How to Install macOS on an External Drive: The Ultimate Guide Once the download finishes