The best smart rings of 2025: Testing Oura, Ultrahuman, Samsung, more

Read our full review of the Oura Ring 4.

If you want a holistic view of your health that includes daily metrics alongside long-term analysis of stress resilience, chronotype, and cardiovascular health, the Oura Ring 4 delivers it all. It has the slimmest, most comfortable fit of all the rings we tested, so you can forget you’re wearing it day and night.

Its companion app is well-designed and organized for easy navigation, so you can glance at your data quickly. Its AI algorithms synthesize data into quick but thorough summaries so you know your readiness for the day. It is the most expensive ring we tested and requires a subscription fee of $5.99 monthly or $69.99 annually, so you must be prepared to make a long-term investment with the Oura Ring.

Oura Ring made a name for smart rings. While other competitors have entered the field since its 2015 Kickstarter campaign, Oura remains the most popular option, and it’s warranted. The Oura Ring 4, the latest iteration from the brand, is the most comfortable, accurate, and well-designed smart ring we’ve tested.

The ring contains a red and infrared LED, a green and infrared LED, a movement-tracking accelerometer, and digital temperature monitors that all work together to calculate your biometrics, which are presented in the app. With a slim fit and rounded edges, it looks like a classic band that blends right into your wardrobe but remains comfortable without digging in or pinching your finger. Unfortunately, Oura charges extra for certain finishes (you’ll pay $150 more if you want gold instead of silver). After several weeks of testing, my Oura ring shows quite a few scratches from daily wear.

All of the sensors produce accurate data. I wore it simultaneously with an Apple Watch; its step count and heart rate were always on par. It also seamlessly connects with the Apple Watch. Tracking activity directly in the Oura app requires you to pull out your smartphone; however, when paired with the Apple Watch, I could start my workout on the watch, and it would automatically upload to the Oura app. And if I ever forgot to start a workout, Oura would have suggested activity time to add to my log.

While Oura is great at providing a quick snapshot of your data in the ‘Today’ tab of the app, like a readiness score calculated from sleep, heart rate, and the previous day’s activities, it’s also invested in long-term health data. Under the ‘My Health’ tab, it calculates stress resilience, cardiovascular age and capacity, and chronotype for deeper insights into your overall health.

In addition to being compatible with Apple Watch, it works with other apps, including Clue and Natural Cycles, to provide insights into cycle tracking.

The biggest drawback of Oura is its required subscription. You can technically use it without one, but it limits all the data you see. Without a subscription, you can only see your Readiness score, sleep score, and activity, and you won’t get all of the extra health insights.