iOS 12.0 (build 16A5318d) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-07-03T17:05:35Z. The update package is 420.54 MB. This is a delta (partial) update that requires 12.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5ccd21e8d0d714c1094169f8a6567627a80ee3f1.zip.