iOS 11.4 (build 15F5077a) is an official Apple over-the-air update for the iPhone 5s (GSM), released on 2018-05-14T17:17:14Z. The update package is 248.84 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 31c7e11ae3710f30d2610f919d8220cc7b423e9d.zip.