iPadOS 12.3 (build 16F5139e) is an official Apple over-the-air update for the iPad Air (WiFi), released on 2019-04-22T17:07:43Z. The update package is 347.42 MB. This is a delta (partial) update that requires 12.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 016ebbdbfae5bcad11dae68963df3af3c00356aa.zip.