iPadOS 9.1 (build 13B5143) is an official Apple over-the-air update for the iPad 4 (WiFi), released on 2015-10-21T17:15:45Z. The update package is 1.17 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: fc4888b325d15df95e4092a89980d166e2468df9.zip.