tvOS 13.3.1 (build 17K795) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-01-28T18:42:29Z. The update package is 940.29 MB. This is a delta (partial) update that requires 12.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a092be10627cef0b41d0b39c6613c4ac1bcaecc1.zip.