iOS 9.3 (build 13E233) is an official Apple over-the-air update for the iPhone 4s, released on 2016-03-21T18:56:12Z. The update package is 254.48 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f5458847ef2b37aceba5ed36781195ddb708eae5.zip.