iOS 12.3 (build 16F5139e) is an official Apple over-the-air update for the iPhone 6, released on 2019-04-22T17:08:58Z. The update package is 301.58 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9f7c4fde8cabeae99d1732b337668e84c22cec98.zip.