Circular Ring 2 review: I wanted to love it, but the software got in the way

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Circular Ring 2: One minute review

The Circular Ring 2 is an ambitious smart ring. On paper, it has almost everything you need. Alongside standard health, recovery and sleep tracking, it offers features you won’t find on many rivals, including electrocardiogram (ECG) readings and atrial fibrillation (AFib) detection. Circular is also promising blood pressure and blood glucose trend monitoring in future updates.

At first glance, it feels like a genuine challenger to the likes of Oura, RingConn and Samsung. The ring itself looks good, feels lightweight on the finger and comes with a charging case, which is a welcome upgrade over the previous Circular model. Battery life is solid too, lasting around six days during my testing.

But unfortunately, the day-to-day experience doesn’t live up to that impressive spec sheet.

Circular Ring 2: Specifications

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Component	Circular Ring 2
Price	£280 (black), £360 (silver), £440 (rose gold, gold) / $349, $449, $549 / AU$497, AU$639, AU$782
Dimensions	2.55mm thick, 7.8mm wide
Weight	3g
Finish	Black, silver, rose gold, gold
Sizes	6 to 14
Material	Titanium body, hypoallergenic interior with a PVD coating
Battery life	Up to 8 days (power mode); 5 days (performance mode)
Sensors	ECG, PPG, temp sensor, 3x accelerometer
Connection	Bluetooth
Water resistance	Fully waterproof (rating not specified)

A close up of the sensors inside the circular ring 2 smart ring — (Image credit: Future / Becca Caddy)

Circular Ring 2: Price and availability

Pricing starts at £280 / $349 / AU$497
Rolled out after a Kickstarter release in late 2025 / early 2026
No subscription needed, but premium features expected soon

Rather than arriving as a traditional retail release, the Circular Ring 2 began life as a Kickstarter project in 2025 before gradually rolling out to customers through late 2025 and into 2026.

Pricing starts at £280 / $349 / AU$497 for the black version, rising to £360 / $449 / AU$639 for the silver model I tested. The gold and rose gold finishes sit at the top of the range at £440 / $549 / AU$782.

At first glance, the Circular Ring 2 looks competitively priced. One of its biggest selling points is that it doesn’t require a mandatory subscription to access core features, unlike the Oura Ring 4, which starts at £349 / $349 / AU$534 and also requires an additional monthly membership fee of £5.99 / $5.99

However, the picture becomes a little more complicated when you look closer. Circular is already promoting upcoming premium features, including blood pressure and blood glucose trend monitoring, which aren’t available but are expected soon. The company says these features will either require a subscription or can be unlocked using Circular Coins, which are earned through regular use, but details remain limited and pricing has yet to be confirmed.

Looking across the wider smart ring market, the Circular Ring 2 sits in a crowded middle ground. It’s cheaper than the Samsung Galaxy Ring, which starts at £399 / $399 / AU$699, but more expensive than the RingConn Gen 2 at £299 / $299 / AU$460. There are also budget-focused options now, like the Amazfit Helio Ring, which costs significantly less at £149.90 / $149.99 / AU$269.

The problem isn’t necessarily the asking price here but more that the performance doesn’t justify it. While the Circular Ring 2 undercuts some of the biggest names in the category, like Oura, Samsung and RingConn, they all currently offer a more polished experience. That makes the Circular Ring 2 difficult to view as good value, even before any future premium features are brought into the equation.

Becca holding the circular ring 2 above its charging case

(Image credit: Future / Becca Caddy)

Circular Ring 2: Design

Lightweight, slim design
Silver color doesn’t scratch
Nice new charging case included

I liked the design of the Circular Ring 2. The fit was very comfortable throughout testing, even when I was sleeping, and at just 2g it felt light on my finger. The silver finish also looks fairly premium.

Circular offers a wide range of sizes here, from 6 to 14, which beats most rivals. I tested a size 8 on my left index finger, which matched the recommendation from Circular’s new digital AI sizing tool.

While the company still offers a traditional sizing kit as well, it’s nice to see a less wasteful digital alternative that actually proved accurate in my case. Especially considering you’ll need to pay an extra £5 / $5 for Circular’s traditional sizing kit.

The Circular Ring 2 has softer, more rounded edges than rivals like the RingConn Gen 2 or previous Circular Ring Slim. Whether that’s a positive or negative will come down to personal preference, but it does make the ring feel slightly chunkier than some competitors despite it being one of the slimmest choices available at 2.5mm thick. A small circular logo on the outer edge makes it easy to get the right way round so that the sensors are where they need to be.

I tested the silver model, which I’d recommend over the black version. Black smart rings tend to show scratches more easily, and that was one of the big problems on the previous Circular Ring Slim. After two weeks of wear, my ring had picked up a few minor scuffs but was in good condition overall.

Another welcome improvement here is the charging case. Unlike the Circular Ring Slim, which relied on a charging cable and small plinth, the Ring 2 ships with a compact clamshell charging case that’s easy to carry and use.

Overall, the ring’s design is one of the Circular Ring 2’s biggest strengths. The company has clearly refined the hardware. Unfortunately, as we’ll see later, the software hasn’t evolved at the same pace.

The circular ring 2 smart ring pictured on a grey surface next to its charging case — (Image credit: Future / Becca Caddy)

Circular Ring 2: Features

Lots of features
ECG and AFib
Glucose and blood pressure readings on the way

The Circular Ring 2 has an ambitious set of features. Alongside standard health, sleep and activity tracking, it measures metrics like heart rate, heart rate variability (HRV), blood oxygen saturation (SpO2), skin temperature and breathing rate.

There are also women’s health features designed to track hormonal shifts and fertility, plus stress monitoring, guided breathing exercises, medication reminders and an AI assistant called Kira.

The headline features are ECG measurements and AFib detection, both of which are rare in smart rings. Circular is also promising blood pressure and blood glucose trend monitoring in future updates, though neither feature was available during testing and both will sit behind a premium-ish model when they arrive. Blood pressure is not easy to measure with LED-based optical heart rate sensors, without an inflatable cuff for calibration: it will be interesting to see what form the blood pressure feature eventually takes, and whether it will be accurate.

On paper, it’s an impressive package that rivals, and in some cases actually exceeds, what you’ll find from bigger names in this space.

The circular ring 2 smart ring pictured in its charging case — (Image credit: Future / Becca Caddy)

Circular Ring 2: Performance

Disappointing app
Slow to sync and update
Battery life is improved

The Circular Ring 2 made a good first impression. Basic metrics like steps, heart rate and sleep tracking all seemed reasonable during the first few days of testing. But the longer I wore it, the more problems started to emerge.

The biggest issue is the app. Smart rings don’t have screens, which means if you think about it, the app effectively is the product, much like a Whoop band. That’s where the Circular Ring 2 falls behind rivals.

Syncing is frustratingly slow. Pulling data from the ring often took several minutes and occasionally failed altogether, forcing me to try again. That might sound like a small complaint, but it adds unnecessary friction. Several times I found myself opening the app, waiting for data to sync, then simply closing it again. If I owned this ring long-term, I suspect I’d eventually stop checking the app altogether.

The app itself feels cluttered and unintuitive. Health insights, scores, charts and features are scattered across multiple screens, while the home page is filled with circles, cards and widgets competing for attention. Even as someone who tests wearables for a living, I often found it harder than it should be to locate specific information.

The language doesn’t help either. As mentioned above, the app kept telling me my sleep was “Incorrect”, or my body was “unbalanced”, which left me confused rather than enlightened.

The AI assistant, Kira, wasn’t much better, largely repackaging existing data in a confusing format with tiny fonts and a huge chunk of text with generic recommendations, like “stay hydrated”. Some of the ring’s most exciting features also failed to deliver. ECG and AFib monitoring never fully worked during my testing, repeatedly getting stuck on a loading screen.

Sleep tracking was generally accurate when I followed a conventional sleep schedule, but it struggled with fragmented sleep and occasionally recorded inaccurate sleep times. On several occasions I woke up for a few hours before going back to sleep, only for the ring to record the entire period as one continuous sleep session.

Workout tracking isn’t what smart rings do best. But here it still feels like an afterthought. Sports Sessions are hidden away, must be started manually and there’s no automatic workout detection, unlike competitors like the Oura Ring 4 and Samsung Galaxy Ring. I also experienced a handful of smaller bugs, including random disconnections and occasional time zone changes despite not travelling anywhere.

Battery life is one area where the Circular Ring 2 performs well. Circular promises up to five days in Performance Mode and I managed six days during testing. That’s competitive with most major rivals and a significant improvement over the Circular Ring Slim.

Overall, the Circular Ring 2 feels like a smart ring with excellent ideas but inconsistent execution. Yes, the hardware is good, the feature list is impressive and the battery life is solid. But the software experience remains frustratingly rough around the edges, and in an increasingly competitive smart ring market, that’s difficult to overlook.

The circular ring 2 smart ring pictured on a grey surface

(Image credit: Future / Becca Caddy)

Circular Ring 2: Scorecard

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Category	Comment	Score
Value	There’s no subscription, which makes it seem like good value. But once you factor in the inconsistent performance and the strength of the competition, it’s difficult to justify the price.	2.5/5
Design	Lightweight, comfortable to wear and I liked the charging case. It doesn’t stand out against the best-looking smart rings on the market, but the hardware feels thoughtfully designed with minimal signs of wear.	4/5
Features	An impressive range of health, wellness and sleep tracking features, including ECG and AFib monitoring. The challenge isn’t the breadth of features available, but the fact that some are still missing despite being promised.	4/5
Performance	The feature set is promising, but it’s held back by slow syncing, buggy behavior and an app that feels cluttered and unfinished. Battery life is good, but an overall lack of polish makes it difficult to recommend.	2.5/5

Circular Ring 2: Should I buy?

Buy it if…

Don’t buy it if…

Also consider

How I tested

Becca holding the circular ring 2 smart ring against a grey surface — (Image credit: Future / Becca Caddy)

I tested the Circular Ring 2 for 2 weeks. I wore it 24/7 and only took it off to charge it and when I was lifting weights — I learned the hard way testing smart rings over the years that they’re very easy to scratch. It was on throughout workouts, working, socializing, relaxing on an evening and sleeping at night.

I’ve been reviewing smart rings since the very first iteration of the Oura ring came out in 2017 and have tested almost every generation from every smart ring brand since. Which puts me in a great position to compare models, tell you which is right for you and bring you that all important context about the smart ring industry.

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