Here you can download the official macOS 10.12 Sierra ISO for free.
macOS Sierra (version 10.12) is the thirteenth major release of macOS (formerly known as OS X and Mac OS X), Apple Inc.’s desktop and server operating system for Macintosh computers. The name “macOS” stems from the intention to unify the operating system’s name with that of iOS, iPadOS, watchOS and tvOS. Sierra is named after the Sierra Nevada mountain range in California and Nevada. Its major new features concern continuity, iCloud, and windowing, as well as support for Apple Pay and Siri.
Download macOS 10.12 Sierra:
Architecture: Intel x86
File-Format: ISO
Download: Apple.com
Download: Archive.org
