iOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2016-03-31T16:54:36Z. The update package is 1002.8 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 0a433d2b45f25ea7e5649cb98169b3a284e716d1.zip.