tvOS 13.4 (build 17L256) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-03-24T17:17:26Z. The update package is 1.15 GB. This is a delta (partial) update that requires 11.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 6801c3d0ffdae4677113ed9d93b62fc02e00680b.zip.