iPadOS 9.3.1 (build 13E238) is an official Apple over-the-air update for the iPad mini 4 (WiFi), released on 2016-03-31T16:54:02Z. The update package is 270.75 MB. This is a delta (partial) update that requires 9.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e06c43603f63cca03c7cde57486a3c2b1849f57f.zip.