iOS 12.0 (build 16A5362a) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-08-20T17:05:24Z. The update package is 157.93 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: 76fb6355cc5ab7a16f88c57a2f2485ba2e771e28.zip.