iOS 12.3 (build 16F5148a) is an official Apple over-the-air update for the iPhone 6, released on 2019-04-29T17:36:11Z. The update package is 89.94 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: fcb31da7422387422f93907ae96b8c3548b88bb5.zip.