watchOS 6.3.1 (build 17U224) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2026-02-02T18:44:36Z. The update package is 297.93 MB. This is a delta (partial) update that requires 6.2 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 94e49636a45b55f70153a8b76c5957e58d1cd6ea.zip.