Apple released a small build update to iOS 26 developer beta 6, which does not re-enable the blood oxygen sensor on Apple Watch in spite of the earlier iOS 18.6.1 update that did.
Apple has found a way to bring back the blood oxygen sensor to the Apple Watch via software without violating Masimo patents or an import block. The update went out via iOS 18.6.1 on Thursday, but Apple did not include the change via the iOS 26 developer beta release.
The new iOS 26 developer beta is still beta 6, but it has a slightly new build number — 23A5318f up from 23A5318c. Apple didn’t share why it updated the build, and no notable changes have been discovered as of this publication.
The blood oxygen sensor has been present in Apple Watch models sold since a sales ban began in January 2024, but Apple has simply turned off the feature via software. Devices sold before January 18, 2024 in the United States never lost the feature.
While the import ban remains in place, Apple has clearly found a way around the Masimo patents while being able to enable the blood oxygen sensor. However, users on the developer cycle haven’t gotten the update just yet.
There is a chance that Apple has included the software workaround in the beta releases and could enable it via a backend push later. There have been no reports of the blood oxygen detector actually coming back online after the update.
If you’re not on the beta train, then iOS 18.6.1 and watchOS 11.6.1 are available with the blood oxygen sensor update. Download updates via the Settings app, General, Software Update.
