iOS 12.3 (build 16F5129d) is an official Apple over-the-air update for the iPhone X (GSM), released on 2019-04-08T17:05:00Z. The update package is 403.23 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: 973bbce52efbe65ce80b05d9be0863b005b16428.zip.