Apple makes a bold claim when it comes to Apple Watch Series 12 and Apple Watch Ultra 4 . Apple backs up this claim with a new study that shows how Series 12 heart rate sensing compares to other leading wearables, including smart rings and fitness bands.
The new Health Sensing System on both watches “delivers the most accurate heart rate sensing in a wearable, according to Apple.
Beats USB-A to USB-C Cable | The official CarPlay cable Testing took place across five sites in the US and Malaysia during July and August 2026, according to Apple’s nine-page study . Apple enrolled 1,460 adults, with 1,254 contributing at least one paired measurement to the final analysis. Apple says Series 12 produced statistically better overall accuracy than every comparison device across both workouts and daily living. Across 159 individual activity and measurement comparisons, Apple Watch achieved statistically better accuracy in 139. Apple Watch Series 12 is currently available for pre-order from $399. Apple Watch Ultra 4 is available for pre-order from $799. Both models launch in one week on September 18.
Apple Watch Series 12 and Apple Watch Ultra 4 are a major upgrade due to the Health Sensing System that drives many of the health and fitness features.
“With the release of Apple Watch Series 12 and Apple Watch Ultra 4, Apple introduced the Health Sensing System, which includes both updated electrical and optical (photoplethysmography, or PPG) heart sensors and associated signal processing algorithms, as well as several features enabled by the new technology, such as Recovery HRV and the Readiness app,” Apple explains.
