tvOS 11.4 (build 15L577) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-05-29T17:10:08Z. The update package is 537.47 MB. This is a delta (partial) update that requires 11.2.5 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 65342f0c1f7a73e1fa6d30622e0a8fcf9b67c64f.zip.