iOS 8.3 (build 12F5061) is an official Apple over-the-air update for the iPhone 4s, released on 2015-03-24T16:54:12Z. The update package is 79.22 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: f9ea5e080fb6a3aa81b8bae5f81437a9516bdd38.zip.