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 670.43 MB. This is a delta (partial) update that requires 11.2.6 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a7d5273be82bbe40ac4552232a6c02d380f62d3a.zip.