The Circular Ring 2 is one of the latest smart rings available, having launched in the latter half of 2025. It’s a bit of a departure from Circular’s previous models, offering a streamlined design and experience, although at the cost of some of its predecessor’s more unique features.
I’ve been testing the Circular Ring 2 for a month, and it delivers a lot of what anyone would want in a smart ring. However, in the shadow of Oura, especially after launching the new Oura Ring 5, it feels like the Circular Ring 2 doesn’t really have much room to shine, even with some rather rare smart ring features.
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Category |
Circular Ring 2 |
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Materials |
Titanium body, PVD coating, hypoallergenic interior |
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Protection |
IP68 |
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Sensors |
ECG, PPG, temp sensor, accelerometer |
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Battery |
Performance mode: Up to 4 days Power mode: Up to 8 days |
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Connectivity |
Bluetooth LE |
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Platform support |
iOS (Apple Health), Android (Health Connect) |
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Dimensions |
Width: 7.8mm Thickness: 2.5mm |
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Weight |
3g |
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Sizes |
6-14 |
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Colors |
Black, Gold, Silver, Rose Gold |
Questionable design choices
The Circular Ring 2 features a pretty standard smart ring design, which is mostly symmetrical, aside from two protrusions on the inner side of the ring where the sensors are. The ring is relatively thick at 2.55mm, but that isn’t the problem; those two protrusions dig into my finger, and it can make wearing the ring somewhat uncomfortable.
Frankly, I’m not sure what compelled Circular to design its sensors this way, but it doesn’t promote prolonged wear on something meant to be worn comfortably, especially at bedtime.
Unfortunately, things aren’t much better on the exterior side of the ring. Circular Ring 2 is available in four colorways, and my silver option started off nice, but it quickly took a turn for the worse. The finish on the ring gets scratched and scuffed so easily; it looks like I’ve been wearing my unit for at least a year when it’s only been a month. Granted, I do work out with it, so some of that is definitely my fault, but I often put a rubber cover on it. Even so, just doing regular things such as holding objects can add to wear and tear, which isn’t a good look.
The top of the ring is clearly marked with the Circular logo, making it easy to know how to properly wear it. It’s a nice touch, but I find myself cleaning it often as dirt can easily get trapped here.
Circular’s coolest features aren’t here
Unfortunately, the logo at the top of the ring doesn’t serve as a “button” as it does on the Circular Ring Slim, which launched in 2023. It’s a shame, but there’s an even more disappointing reason as to why: there’s no vibration motor in this ring.
Previous Circular Ring models would vibrate to alert you to notifications or alarms, and, in the case of the Circular Ring Slim, you could tap the top of the ring to stop the vibration.
This would have been a very cool feature to include on the Circular Ring 2, especially if the company could figure out how to implement it with the more streamlined design. Not many health-tracking smart rings feature vibration motors, and it would help the Circular Ring 2 stand out against heavyweights like Samsung and Oura.
When I asked why these features were removed, it seemed they were complicated to implement on such a small device, and the company wanted to focus this model on other areas, such as ECG. That said, it’s up to you to decide if these features are worth it.
But here’s the thing… some of the new features announced for the Circular Ring 2 aren’t even available. The company teased blood pressure and blood glucose trend estimates, features not found in many smart rings. However, despite a planned “early 2026” launch, these features remain unavailable, while other companies like Oura hone in on blood pressure estimates.
The basics
Design may be a bit off, and some features may be missing, but the Circular Ring 2 has pretty much all the features you could need. As a health and fitness tracker, it does a decent job, especially with regard to sleep tracking. It manages to match my other wearables pretty well, including heart rate and changes in body temperature.
I also like that the Circular Ring 2 evaluates how well you wake up, something a lot of people don’t pay much attention to. How you feel when you wake up can be based on how long you slept, but also on the sleep stage you’re in when you wake up.
To help, the Circular app features a built-in alarm with a smart alarm that wakes you at an ideal time, usually during your lightest sleep stage. Some features, like vibration and smart snooze, aren’t available even though they’re clearly present in the app. It feels somewhat like an unfair tease.
On the plus side, ECG measurements and Afib detection are also available, and you can set rhythm monitoring to run daily, weekly, or monthly. It also comes with medication reminders, and you can set up multiple alarms if you need to take multiple medications at different times.
You can track activities with the Circular Ring 2, but this isn’t its specialty. There are a number of activities you can track in the app, and it does a decent job, with real-time heart rate monitoring that you can view directly on the app. It also uses the phone’s GPS for certain activities like walking and running, and you can even view the map of your pathway while exercising.
That said, I find that for workout tracking, the Circular Ring isn’t too reliable and even omits some useful information. I’ve tracked several workouts with the ring, comparing them with other wearables, including the Oura Ring 4, Garmin Venu 4, and Fitbit Air. The Circular Ring 2 often overestimates or underestimates heart rate during these activities, though at times it can be in the ballpark.
Unfortunately, I couldn’t perform a step test because while the Circular Ring 2 features an overall daily step count, it doesn’t appear to count steps during individual workouts. The ring also doesn’t feature any automatic activity tracking, so you’ll have to manually track each workout, which is kind of a bummer.
An imperfect app
The Circular Ring offers a very robust app experience, which I find a bit overwhelming. There’s a lot of information crammed into the main home page, though fortunately it’s mostly visual.
At the top is a row of “circles,” which can be customized to display your most important metrics. You can find your sleep and energy scores here, or tap each metric to dive into them.
That said, you might be waiting a bit to get the most up-to-date information; the app is incredibly slow to sync data with the ring. You can view this process in real time in the app, but it only highlights how slow it is, which is kind of a bummer, since the app is your main point of interaction with the ring and its data.
Fortunately, there are five widgets you can add to your phone: the battery, energy score, sleep score, steps tracker, and an overall wellness summary that includes all of the above and a calendar. In fact, it has more widgets than I find available on many apps I have downloaded, and they’re well designed.
The app also features Kira+, an AI health coach that provides a summary of your metrics and recommendations for your day. Its implementation is pretty clunky, and I often have to manually generate daily recommendations, which isn’t as useful as automatically surfacing each morning.
As for the summaries themselves, Kira+ doesn’t do the best job of displaying them. It’s all squeezed together in a rather dense set of bullet points, where it mostly throws a bunch of numbers at me that don’t mean much, while not doing much to really explain them. Fortunately, the recommendations are a bit easier to take in, but it would be much better if summaries and recommendations were accessible throughout the app and not within a separate tab on the home page.
Still, it’s a decent offering as AI health coaches go, but not close to what you’d find with the likes of Oura’s Advisor or Google’s Personal Health Coach, since you can’t really interact with Kira+.
Battery life and modes
One thing that the Circular Ring features that I don’t find on other rings is its power modes. By default, the Circular Ring 2 is in Performance mode, meaning you’ll get the most accurate data from the ring. Unfortunately, this hurts battery life, so you should only expect about 4 days of use, which is pretty accurate in my testing.
On the other hand, there’s Power mode, which gives you up to eight days of battery life but at the expense of data accuracy. Still, it’s pretty impressive and is on the higher end of battery life offered by smartwatches. You can also easily switch between the two modes in the app, and I recommend using Power mode most of the time and switching to Performance during workouts and sleep, which provides a good middle ground for battery life.
The inclusion of a charging case, rather than a cradle, is a nice addition, so you can carry it with you in case you need a top-up. It’s a decently sized case, no bigger than most wireless earbud cases, but simply setting the ring on the charger won’t do anything; you have to press the button on the back to begin charging. It’s somewhat unintuitive, and I have found I’ve forgotten to press the button a few times, leaving me with a dead ring when I thought it was charging.
Verdict
The smart ring market isn’t quite as robust as I thought it would be, with Oura still dominating and stomping all over the competition. However, smaller companies like Circular are still kicking and proving they can offer compelling alternatives for anyone who doesn’t want to add another subscription on top of the ring’s price.
Unfortunately, the Circular Ring 2 gave up some of its most distinctive features to become a run-of-the-mill smart ring that does just the bare minimum. And even when more compelling features like blood pressure and blood glucose estimations arrive, they’ll be paywalled, meaning you’ll need to be willing to fork over more money, ruining one of Circular’s biggest advantages over Oura.
For $349, the Circular Ring 2 might be priced out of its league. It’s not a bad smart ring, but I think Circular might need to rethink some of its design, app, and feature set to truly compete with the big boys. It may cost $50 less than the Oura Ring 5 if you don’t account for the Oura membership, but I can’t help but think the splurge on Oura might be worth it, especially if you’ll end up paying more for extra Circular features anyway.
Oura alternative
The Circular Ring 2 is a smart ring with great battery life and features like ECG for more comprehensive health monitoring. There’s also no subscription, at least for now, so you can access all its available features for free.