iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad mini 2 (WiFi), released on 2016-03-31T16:53:07Z. The update package is 418.96 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5183a4fd39b3dcd0b6c140a33aaf8d9e0d468f05.zip.