watchOS 5.3.10 (build 16U711) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2026-03-24T18:36:29Z. The update package is 121.09 MB. This is a delta (partial) update that requires 5.2.1 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: 08e172ea7846b4b4205168f71b0938c8d1bea941.zip.