iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad mini 3 (WiFi), released on 2015-10-21T17:15:57Z. The update package is 239.9 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: b926afd97b779a76b018e7548b223955576cb9f2.zip.