iPadOS 11.3.1 (build 15E302) is an official Apple over-the-air update for the iPad mini 2 (WiFi), released on 2018-04-24T17:05:52Z. The update package is 1.2 GB. This is a delta (partial) update that requires 10.3.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 95d2a5b6b4710b7c712e32fcb02284eaba53a933.zip.