If your Mac is compatible, you can view the Sierra page in the Mac App Store to download the installer. macOS Sierra on App Store

Click the official Apple-provided App Store link for macOS Sierra.

Download macOS Sierra 10.12 InstallOS.dmg

List the best still supported on Sierra.

You will need roughly 10GB to 15GB of free space to download and install the software. How to Download macOS 10.12 Sierra Full Installer

Whether you are:

Terminal will display a progress bar. Once completed, the full file will be waiting in your Applications folder. How to Create a Bootable USB Drive for macOS Sierra

Rename Sierra.iso.cdr to Sierra.iso .

Open Safari and click the Direct Mac App Store Link for macOS Sierra .

Press , provide your Mac administrator account password when prompted, and press Y to confirm the drive erasure.

file inside. This will place the actual "Install macOS Sierra" app into your Applications Apple Support 2. Terminal Method (For macOS Catalina or Later) If you are currently on a newer Mac, you can use the softwareupdate