tvOS 11.3 (build 15L211) is an official Apple over-the-air update for the Apple TV 4 (2015), released on 2018-03-29T17:05:08Z. The update package is 988.4 MB. This is a delta (partial) update that requires 9.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: ac47250ef6cd5d54c1d4b1f0f102e9f778d1f374.zip.