tvOS 13.4 (build 17L256) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2020-03-24T17:17:32Z. The update package is 867.93 MB. This is a delta (partial) update that requires 12.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b480c186bd9595a2b175abb50765688cd88f0f2f.zip.