Bootable Installer

An external drive containing a complete macOS installer that can boot a Mac and install or reinstall macOS without requiring network access.

What to Know

Bootable installers provide offline macOS installation capability when Internet Recovery is unavailable due to network issues, firewall restrictions, or extremely slow connections. They also enable downgrading to specific macOS versions when troubleshooting compatibility issues with applications or hardware, a task that Internet Recovery cannot perform since it installs the latest compatible OS. For organizations managing fleets, having bootable installers for multiple macOS versions ensures rapid recovery without dependency on Apple’s servers or local network infrastructure.

Common Scenarios

Enterprise IT: IT teams maintain bootable installers for approved macOS versions to ensure consistent deployment and avoid forced upgrades when using Internet Recovery. This is especially important in regulated environments where specific OS versions must remain in use until software compatibility is validated.

MSP: MSPs keep bootable installers on hand when servicing client sites with poor internet connectivity or restrictive firewalls that block Apple’s recovery servers. Having multiple macOS versions available enables quick downgrade scenarios when clients experience compatibility issues after automatic updates.

Education: School IT departments create bootable installers at the beginning of each school year to rapidly reimage lab Macs during breaks without overwhelming the network or relying on internet access. This ensures predictable imaging times and consistent OS versions across all classroom devices.

In Addigy

While Addigy does not directly create bootable installers, admins can use Addigy to deploy scripts that download and create bootable installers on user devices, or deploy documentation instructing users how to create them. After using a bootable installer to restore a Mac, devices can be re-enrolled in Addigy through ADE or manual enrollment to restore management and policy configurations.