tvOS 13.3 (build 17K449) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2019-12-10T18:33:06Z. The update package is 1.09 GB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f80b2340218976d8c4deefbbed7db8f42d354851.zip.