Download any macOS installer with Terminal

Use Apple's built-in softwareupdate command to download full macOS installers without upgrading.

Since macOS Catalina, the built-in softwareupdate tool can download the complete “Install macOS …” app straight from Apple. Nothing is installed, so it's the cleanest way to get an installer for a bootable USB or a virtual machine.

1. See which installers are available

Open Terminal (Applications › Utilities) and run:

You'll get a list of titles, version numbers and sizes. The list is filtered to versions your Mac is compatible with.

2. Download a specific version

Replace the number with any version from step 1. When it finishes, the installer is in your Applications folder.

3. Check it's there

Troubleshooting

• “Install failed with error: Update not found”: that exact version isn't in Apple's catalog for your Mac. Pick one from the list in step 1.
• Your Mac runs Mojave or earlier: the --fetch-full-installer option doesn't exist there. Use the App Store or direct links on each version page instead.
• The download stalls: installers are 12–15 GB. Make sure you have at least twice that free, and use a wired or stable connection.

Prefer a graphical app? Mist is a free, open-source Mac app that does the same thing with a point-and-click interface.