iOS 8.2 (build 12D5461b) is an official Apple over-the-air update for the iPhone 4s, released on 2015-01-12T17:54:05Z. The update package is 178.46 MB. This is a delta (partial) update that requires 8.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: c3f42d5a496a8f505c7041d3ef1d67d56d47925f.zip.