Download an older macOS installer from Apple

Check what Apple offers for this Mac

On a Mac running Catalina 10.15 or newer, open Terminal and list the available full installers:

softwareupdate --list-full-installers

Choose a version in that result, then replace [version] below with its number:

softwareupdate --fetch-full-installer --full-installer-version [version]

The download creates an installer in Applications. This command downloads the installer; open it separately when ready. Apple explains the method in its macOS download instructions.

If you see “update not found”

Apple says that version is unavailable for your Mac. Return to the list instead of guessing a different filename or trusting a mirror. A compatibility list does not establish that every old point release remains downloadable.

For example, wanting Sequoia 15.5 or 15.6.1 does not prove Apple still offers it for an M4 Mac. This guide does not promise a working download for either build.

Choose the right official method

• Full installer: an Install macOS app used to install the operating system. Apple's download article also provides App Store routes for older releases and browser downloads for some earlier systems.
• Update package: a patch for an existing installation. An old update package is not a replacement for a full installer.
• Bootable installer: a USB installer made from the full app. Follow Apple's bootable-installer instructions; creating the USB volume erases that volume. The target Mac must support the release and may still need internet access.
• Firmware revive or restore: a separate repair workflow for Apple-silicon or T2 Macs using another Mac. Apple distinguishes revive from restore; restore erases the affected Mac. This is not a verified way to obtain any desired older version.

What Recovery can reinstall

On Apple silicon, Recovery normally reinstalls the current version of the most recently installed macOS. On Intel, the Recovery startup keys affect which release is offered. Apple's Recovery instructions explain those choices; they do not promise a particular historical patch.

Erase All Content and Settings keeps the installed operating system. It is not a downgrade selector.

Before opening an installer

Back up your files, match the exact Mac model to Apple's compatibility list, and check the apps and accessories you need. A version your Mac never supported is not made compatible by a USB installer. See our Sequoia model check or the separate Catalina download guide.

If an installer remains unavailable or fails, use Apple's installation-error guidance. Repeated failures, beta downgrade problems and Bluetooth faults need their own diagnosis; choosing an installer does not resolve them.