watchOS 6.3.1

watchOS

Version

6.3.1

Build ID

17U224

File Size

542.55 MB

Release Date

2026-02-02T18:44:41Z

Update Type

Normal release

Delta update - requires 6.1.3 installed first.

Download OTA

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

About This Update

watchOS 6.3.1 (build 17U224) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2026-02-02T18:44:41Z. The update package is 542.55 MB. This is a delta (partial) update that requires 6.1.3 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 901c63061cfbdb8727d1dc479c21a8296ab12b81.zip.

Direct URL

https://updates.cdn-apple.com/2025FallFCS/patches/047-32164/1922171A-008E-4E34-B390-F90DE0B2B8B6/com_apple_MobileAsset_SoftwareUpdate/901c63061cfbdb8727d1dc479c21a8296ab12b81.zip