iPadOS 9.1 (build 13B143) is an official Apple over-the-air update for the iPad 4 (Global), released on 2015-10-21T17:15:53Z. The update package is 925.32 MB. This is a delta (partial) update that requires 8.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9f1e12a67e8b4fd58f58d6b2dd9b42bcd6506f77.zip.