iOS 9.3.1 (build 13E6238) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2016-03-31T16:50:35Z. The update package is 1.35 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 2cb295a96db692457e61f813a0c9ab891265aba0.zip.