iOS 9.3 (build 13E5181f) is an official Apple over-the-air update for the iPhone 4s, released on 2016-01-14T18:01:21Z. The update package is 19.97 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: cf1ee0853fb5e1848e4ca5f16662d3983450ab16.zip.