iOS 9.3 (build 13E233) is an official Apple over-the-air update for the iPhone 4s, released on 2016-03-21T18:56:13Z. The update package is 1.11 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: 4c850f47e8781d3ca5c4b9896ee68302329c9a7c.zip.