iOS 9.3 (build 13E5181f) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2016-01-14T18:01:24Z. The update package is 28.01 MB. This is a delta (partial) update that requires 9.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 118e2cc368f0e449d78e47946825a37276845f20.zip.