iOS 10.2.1 (build 14D27) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2017-01-23T18:08:16Z. The update package is 1.07 GB. This is a delta (partial) update that requires 9.3.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 926cba61627c744deaddccd4ac1b9b66c3b476dc.zip.