iOS 8.3 (build 12F5061) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2015-03-24T16:54:13Z. The update package is 134.56 MB. This is a delta (partial) update that requires 8.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 7d3a742bab8f2092493409bce855e9db0da07b33.zip.