Apple Watch’s Blood Oxygen Monitor Is Back
Great news for Apple Watch fans: the blood oxygen sensor is back.
Apple made the announcement in a short press release on Thursday . The company says the feature has been “redesigned” and will be available to Series 9, Series 10, and Apple Watch Ultra 2 users in a software update coming later today.
Apple initially released a blood oxygen sensor with the Apple Watch Series 6 to allow users to both passively and actively monitor their blood oxygen levels throughout the day. However, shortly after, in 2020, Masimo, a pulse oximeter maker, sued Apple for patent infringement. In January 2024, Apple was briefly banned from selling the Apple Watch Series 9 and Ultra 2 in the US, and as a result, the blood oxygen feature was removed from those watches via a software update. The company resumed selling those watches with the sensor disabled, and did the same with the Series 10 after they were released.
Apple says a recent U.S. Customs ruling has allowed the company to turn the monitors back on. The company countersued Masimo , alleging that Masimo infringed Apple’s patents. In October 2024, a Delaware jury ruled that Masimo did infringe two of those patents.
If you’re wondering why the blood oxygen sensor on your Apple Watch has been working for the past year and a half, there are likely a few explanations. First, the decision only affected Apple Watches sold in the United States. If you bought your watch in another region, Apple didn’t have to disable the oxygen sensor on your device. Second, the feature only had to be disabled on watches that Apple actively manufactured and sold in the United States after January 2024. That means the Apple Watch Series 6, Series 7, Series 8, and Ultra 1 have had functioning sensors all along.
How to Get Blood Oxygen Monitoring Back on Apple Watch
To access the updated blood oxygen sensor, you’ll need to update your compatible watch to watchOS 11.6.1 and your iPhone to iOS 18.6.1. You can find the updates for both devices under Settings > General > Software Update .
This tool can be useful, but it’s not necessarily medically sound. As Lifehacker’s senior health editor Beth Skuerecki explains , the numbers you get aren’t that informative without a consultation with a doctor, who will likely be relying on their own equipment to analyze your health. In other words, it’s great to have the option, but if you’re not feeling well, you’ll probably still need to see a doctor.