tvOS 12.3 (build 16M5146a) is an official Apple over-the-air update for the Apple TV 4K, released on 2019-04-29T17:44:37Z. The update package is 1.57 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: 24ee4e2a023108a85b1e9dfafede70d69c09fa3c.zip.