iOS 9.3 (build 13E233) is an official Apple over-the-air update for the iPhone 6, released on 2016-03-21T18:56:30Z. The update package is 300.59 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 719404480e7528cc2c661581e5e70a971d651a9a.zip.