iOS 9.3 (build 13E5231a) is an official Apple over-the-air update for the iPhone 4s, released on 2016-03-07T17:48:44Z. The update package is 29.02 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: 62fe2ba7cbdf75b13688a06d495467bdd6d33d7d.zip.