iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone 8 (GSM), released on 2018-03-29T17:11:29Z. The update package is 748.02 MB. This is a delta (partial) update that requires 11.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 67e30426802cd514c7b59750d070db4402b3445a.zip.