watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2026-03-24T18:36:26Z. The update package is 466.04 MB. This is a delta (partial) update that requires 5.1.2 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: b73ea0bcc9b771c17d6c05861a6449a043dc25ab.zip.