iOS 11.3 (build 15E216) is an official Apple over-the-air update for the iPhone SE, released on 2018-03-29T17:13:12Z. The update package is 718.75 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: 2150ece7634371ad2e640e41b0e2de6fc55c3e80.zip.