iOS 9.3 (build 13E237) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2016-03-28T16:52:48Z. The update package is 329.09 MB. This is a delta (partial) update that requires 9.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c34b40982efc3520f3fba7e579b4333b2dd74f27.zip.