iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad mini 4 (WiFi), released on 2016-03-31T16:54:01Z. The update package is 424.79 MB. This is a delta (partial) update that requires 9.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9457be78dc14e4d027be5370207ef333feae15a5.zip.