iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad mini 4 (Cellular), released on 2015-10-21T17:15:58Z. The update package is 264.13 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: 948dfbe90c983fa064e78b28d01158a7dec8ad1f.zip.