iOS 10.3.1 (build 14E304) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2017-04-03T17:00:26Z. The update package is 513.4 MB. This is a delta (partial) update that requires 10.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c41a795ce1c955baf68c03e68abd42afa797da54.zip.