iOS 11.4 (build 15F79) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-29T17:15:59Z. The update package is 674.75 MB. This is a delta (partial) update that requires 11.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1fecaced3e1b3d5d08120616c8537a4a0289b844.zip.