iOS 9.3 (build 13E233) is an official Apple over-the-air update for the iPhone 5 (GSM), released on 2016-03-21T18:56:14Z. The update package is 904.96 MB. This is a delta (partial) update that requires 8.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c06407a9b965935ce06d30bc4d167badf5a99c73.zip.