http://wccftech.com/download-macos-high-sierra-final-mac-app-store/

Good news everyone – you can now download macOS High Sierra final version on your Mac. We have the direct Mac App Store download link.

Announced at WWDC 2017, macOS High Sierra is finally available to download for everyone. But the best thing about this release is that if your Mac can run macOS Sierra, then you can upgrade to High Sierra as well.