iOS 12.1.3 (build 16D39) is an official Apple over-the-air update for the iPhone X (GSM), released on 2019-01-22T18:09:23Z. The update package is 486.12 MB. This is a delta (partial) update that requires 12.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: cfe99f7aa3987140d405420d73c56bd4bb8be1ae.zip.