tvOS 13.4 (build 17L256) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-03-24T17:17:30Z. The update package is 871.87 MB. This is a delta (partial) update that requires 12.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 75f876838090f900f0ac77477ef47f14d5af6426.zip.