iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2018-03-29T17:11:28Z. The update package is 798.15 MB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 2b58b460f7d10d22a80ee7eed42b8df83cbffa56.zip.