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 359.05 MB. This is a delta (partial) update that requires 9.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 97c3fd6b83685ba869dfba508ea23a9e7d1113e9.zip.