iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 6, released on 2019-01-22T18:10:30Z. The update package is 404.95 MB. This is a delta (partial) update that requires 12.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d54351dad143ffad64bc84c30046b5f41183efe5.zip.