watchOS 6.3.1 (build 17U224) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2026-02-02T18:44:26Z. The update package is 581.66 MB. This is a delta (partial) update that requires 6.1 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 260ef03c66344565b96788a65abde0e2f3c5b3d0.zip.