iOS 8.1 (build 12B407) is an official Apple over-the-air update for the iPhone 4s, released on 2014-10-07T18:06:07Z. The update package is 27.77 MB. This is a delta (partial) update that requires 8.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 597e2a6ef90391da5433b3dc98a1f78b2e545383.zip.