iPadOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2019-01-22T18:03:56Z. The update package is 1.16 GB. This is a delta (partial) update that requires 11.4 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 3ae8fa0db067d259881114cdc2d8e1ca33092dd0.zip.