iOS 12.1 (build 16B92) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-10-30T17:16:26Z. The update package is 1.37 GB. This is a delta (partial) update that requires 11.0.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 55b39289a2195a74b95a27ddeb5fad32f331083f.zip.