watchOS 6.3.1

watchOS

Version

6.3.1

Build ID

17U224

File Size

250.54 MB

Release Date

2026-02-02T18:44:36Z

Update Type

Normal release

Delta update - requires 6.2.6 installed first.

Download OTA

Looking for beta firmware? View beta builds for Apple Watch Series 4 (44mm) →

About This Update

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 250.54 MB. This is a delta (partial) update that requires 6.2.6 to already be installed on the device - it cannot be applied from scratch. This update is currently signed by Apple, so it can be applied directly from Settings › General › Software Update.

The OTA payload file is a2f3c40cb9f739e1b25f226d850a9539bfcac4fd.zip.

Direct URL

https://updates.cdn-apple.com/2025FallFCS/patches/047-32145/70BABB12-B0F2-4BAD-A42F-87E0615B22DB/com_apple_MobileAsset_SoftwareUpdate/a2f3c40cb9f739e1b25f226d850a9539bfcac4fd.zip