Apple wasn't kidding when it claimed that the Apple Watch Series 12 has the best heart rate accuracy of all wearables, but the extensive study also shows just how close some key rivals are under certain test conditions.
Other than the return of the popular ceramic casing, the Apple Watch Series 12's most significant update was in its improved health sensing system. Central to this is how the new Series 12 and the Apple Watch Ultra 4 monitor heart rate every five seconds.
Apple's Deidre Caldbeck, senior director of Apple Watch and health product marketing, said during the launch that the company had tested it against rivals. Now Apple has published the results of that test.
Naturally it wouldn't have published the results if it weren't true that the Apple Watch comes out top. But deep in the detail, Apple has published just where rivals meet or exceed it in certain areas.
The tests involved 1,460 people who wore a Polar H10 ECG chest strap as reference. Then at the same time, they would wear an Apple Watch on one wrist, while on the other hand they had one of the following:
- Garmin Forerunner 970
- Google Pixel Watch 4
- Huawei Watch 5
- Oura Ring 5
- Samsung Galaxy Watch 8
- WHOOP 5
All of these, apart from the Apple Watch, monitor heart rate more during workouts. In those, the Garmin Forerunner 970 measured heart rate much more often, doing so between every 0.25 and 0.5 seconds.
The most significant improvements in Apple Watch concern health - image credit: Apple.
The Huawei Watch 5, Samsung Galaxy Watch 8, and WHOOP 5 all measured heart rate every 2 seconds. The Oura Ring 5 and Google Pixel Watch 4 measured every 5 seconds, like the Apple Watch.
Things change considerably when a user is not exercising, or at least they do for the Samsung and the Oura. The Galaxy Watch 8 only checks once per minute, and while the Oura Ring varies, it's measuring around every 300 seconds.
As well as the rate of measurement, Apple's test included examining accuracy. For this, Apple Watch "demonstrated a statistically significant higher level of accuracy" in categories called overall workout and overall daily living.
It also had "better accuracy for session-level average heart rate" in most of 12 categories that were tested. It wasn't strictly speaking beaten in any of those tests, but Apple says its margin of victory over the Huawei Watch 5 was not statistically significant in a workout test.
Also in eight tests over activities such as cycling and strength testing, Apple Watch did show "better accuracy for the majority of devices in most activities." But for those eight, the conclusions were indeterminate.
One place where Apple admits to being beaten is in what it called a daily living protocol. Again eight conclusions were statistically indeterminate, but in one case the Pixel Watch 4 showed higher accuracy.
That was for what Apple describes as a rest condition only. Apple then stresses that this greater accuracy was "less than a margin of 0.5" beats per minute.
Where else Apple Watch wins
Apple obviously includes health sensing hardware, but it also works to make that data accessible for the user. There's the whole Health app, plus the ability to export the data to doctors if wanted.
That also made it easy to measure the results across all of the tests, and that wasn't the case with every device. According to Apple's research study, the Samsung Galaxy Watch 8 would only export minimal time stamps "and a single additional heart rate value whose derivation is not documented."
Then the Oura Ring simply wasn't tested during strength training. That's reportedly because the manufacturer recommends not even wearing the ring during weightlifting.
Apple's report gives more detail for the testing methodology, plus a finer breakdown of every result. Ultimately what it tells us is that all wearables provide significant health features, but again it is reportedly true that Apple Watch is overall the most accurate.
This report follows one from January 2026, where a study praised the Apple Watch's usefulness in identifying atrial fibrillation in asymptomatic patients.
