iOS 10.3.1 (build 14E304) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2017-04-03T17:00:29Z. The update package is 25.64 MB. This is a delta (partial) update that requires 10.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fe963fcea9e6349f321f07edb49d9f49fde10a46.zip.