iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone 6, released on 2019-01-22T18:10:27Z. The update package is 1.38 GB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: cb0db129ad530b985a3c1682495494250d3e256f.zip.