iOS 8.1 (build 12B5411) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2014-10-20T17:59:02Z. The update package is 1.89 GB. 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: 1849ac282911c7ee931e5708e7414456b19660be.zip.