Smart Ring Showdown: Why the New Circular Ring 2 May Outshine Oura and the Rest

Key Takeaways and Quick Facts

• Circular Ring 2 is a major upgrade over its first-gen predecessor, with a titanium build, FDA-cleared ECG for AFib detection, and no subscription fees theverge.com thenextweb.com. It addresses past issues in accuracy, design, and battery life, aiming for a “more luxurious, quality-built product,” according to Circular’s cofounder theverge.com.
• Comprehensive health tracking: Circular 2 monitors 140+ biomarkers 24/7 – including heart rate, heart rhythm (ECG), blood oxygen (SpO₂), HRV, skin temperature, sleep stages, stress, and more – and provides actionable insights via its built-in AI coach “Kira” circular.xyz theverge.com. It’s the first smart ring with medical-grade ECG capabilities, enabling on-demand EKG readings and irregular heart rhythm alerts (AFib) right from your finger theverge.com wareable.com.
• No subscription model: Unlike some competitors (notably Oura), Circular 2’s full feature set is available with a one-time purchase – no monthly fees to unlock your data thenextweb.com. This includes advanced features like sleep analysis, personalized energy and recovery scores, guided breathing exercises, smart alarms, and even medication reminders at no extra cost circular.xyz circular.xyz.
• Improved battery & charging: Battery life has roughly doubled from the previous model – about 4 days in full tracking mode, up to 7–8 days in power-save mode theverge.com thenextweb.com. Circular 2 also introduced a convenient wireless charging dock (replacing the flimsy USB charger of gen1), making it easier to top up the ring theverge.com.
• Design and comfort: Crafted from premium titanium in four finishes (black, silver, gold, rose gold), the ring is durable yet featherlight at just ~2 grams circular.xyz. Users and reviewers report it feels sleek and comfortable for 24/7 wear, despite the packed sensors inside tomsguide.com. The completely enclosed form and polished metal finish give it a jewelry-like elegance, far surpassing the plastic look of the original Circular Slim theverge.com.
• Digital sizing innovation: Circular 2 eliminates the usual hassle of ordering plastic sizing kits. Using a smartphone camera and a credit-card-sized reference, buyers can measure their ring size digitally in seconds – a process that worked “remarkably well” in hands-on tests tomsguide.com tomsguide.com. This not only speeds up delivery (no waiting for a sizing kit) but also cuts waste, solving a “down-right antiquated” pain point in smart ring shopping tomsguide.com tomsguide.com.
• Smart features and trade-offs: While the new model doubles down on health and fitness, it did sacrifice the built-in haptic motor that the first-gen had for silent alarms/notifications theverge.com. This means Circular 2 doesn’t vibrate for calls or texts – a conscious trade-off to accommodate better sensors and accuracy. The ring still offers a smart alarm feature (waking you at an optimal point in your sleep cycle via the app) and critical vital alerts on your phone if your HR or SpO₂ crosses thresholds circular.xyz circular.xyz, but general phone notifications on the ring are not present in this iteration.
• App and ecosystem: The Circular app (Android & iOS) acts as your wellness dashboard and personal coach. It presents data with color-coded graphs and daily scores (Sleep, Energy, etc.), and Kira, the AI assistant, suggests tailored tips (e.g. bedtime adjustments, breathing exercises) based on your trends circular.xyz theverge.com. The app has been overhauled for the Ring 2, making the experience smoother and more insightful – calibration for personalized recommendations now takes ~4 days instead of 2 weeks theverge.com. (Integration with Apple Health/Google Fit is expected, although not explicitly detailed.) Importantly, Circular 2’s app works on both iPhone and Android, unlike some rivals that are platform-specific tomsguide.com tomsguide.com.
• Price & availability: The Circular Ring 2 officially launched in early 2025. It was initially offered via Kickstarter (where it raised $4M from 13,000+ backers) and began shipping to backers in July 2025 gadgetsandwearables.com. Retail pricing starts around $349 (basic finishes) up to ~$379 for certain premium coatings foxnews.com. That’s on par with or slightly above an Oura Ring – but again, Circular requires no $5.99/month subscription to unlock features thenextweb.com. Units are now available for direct order via Circular’s site and expected to reach wider retail channels going forward.
• Early verdict: By addressing past shortcomings and adding standout features like ECG, Circular Ring 2 is positioned as one of the most advanced smart rings of 2025. Reviewers who went hands-on at CES noted that Circular “took the laundry list of issues with the Slim and ticked them off one by one” in this redesign theverge.com. It’s poised to give market-leader Oura a run for its money – in fact, one tech writer speculated that Circular Ring 2 “could be the smart ring that cracks the mass adoption code in 2025” thanks to its easier sizing and subscription-free model tomsguide.com.

Circular Ring 2 In-Depth: Features, Specs and Experience

Health and Fitness Tracking

The Circular Ring 2 is packed with sensors and algorithms aimed at quantifying your health from every angle. At its core, it uses optical sensors (PPG) to continuously monitor heart rate, heart rate variability (HRV), blood oxygen saturation (SpO₂), respiratory rate, skin temperature, and more circular.xyz circular.xyz. These biometrics feed into a comprehensive system that analyzes over 140 data points to gauge your daily fitness and wellness.

• 24/7 Heart Monitoring: The ring tracks your heart rate around the clock and leverages it to derive metrics like resting heart rate, training load, and recovery status circular.xyz circular.xyz. Thanks to the ring’s snug finger placement (an optimal spot for PPG readings), Circular claims higher accuracy in heart-rate tracking than wrist wearables circular.xyz. Heart rate variability trends are also recorded to give insight into your autonomic nervous system balance – higher HRV indicates better recovery and resilience to stress circular.xyz.
• First-ever ECG in a Smart Ring: The marquee upgrade in Circular 2 is its electrocardiogram (ECG) sensor. Tiny electrodes inside the ring can capture the electrical signals of your heartbeat on demand, similar to how an Apple Watch ECG works wareable.com wareable.com. This allows for FDA-cleared detection of atrial fibrillation (AFib) and other irregular heart rhythms – a feature no other consumer smart ring offers to date theverge.com wareable.com. In effect, Circular 2 can serve as a discreet heart health companion. “The AFib sensor could provide a warning of an incoming stroke or heart attack — so the tagline has some substance,” notes one report thenextweb.com thenextweb.com. The ECG readings and irregular rhythm alerts are included with the device (no subscription or add-on needed) wareable.com, and Circular partnered with a cardiac tech firm (B-Heart) to ensure medical-grade algorithm accuracy wareable.com.
• Blood Oxygen & Respiratory Tracking: The ring monitors your SpO₂ levels, which can flag issues like sleep apnea or altitude acclimation problems if your blood oxygen drops abnormally circular.xyz. Combined with the breathing rate tracking, it provides a window into respiratory health (for example, a spike in resting breath rate and lower oxygen might indicate illness onset). These vitals can be set to trigger alerts if they cross custom thresholds, acting as an early warning system circular.xyz.
• Activity and Exercise Metrics: Circular 2 isn’t just for passive health monitoring – it also functions as a basic fitness tracker. It counts your steps and active minutes, estimates calories burned, and even can detect specific activities (e.g. running, biking, swimming) using its accelerometer data circular.xyz. Uniquely, the ring supports a Sport Session mode with GPS tracking when connected to your phone, so you can map outdoor workouts like runs or cycling routes circular.xyz. It also estimates your VO₂ max (a key measure of aerobic fitness) over time based on your heart rate during exercises circular.xyz. All these feed into an “Energy” score each day that tallies how well you balanced activity and recovery circular.xyz.
• Stress & Recovery: Through a combination of HRV, sleep, and activity data, Circular computes a daily Stress level and an overall Energy/Recovery score circular.xyz circular.xyz. The app can show you when you may be accumulating too much stress (for example, a low HRV, elevated resting heart rate, and poor sleep might push your stress score high). Circular even offers guided breathing exercises and a “Coherence” training mode to help you lower acute stress — essentially biofeedback breathing drills to sync your heart and mind circular.xyz circular.xyz.
• Women’s Health Tracking: Circular Ring 2 introduces a dedicated women’s health suite. By analyzing patterns in your basal skin temperature, HRV and other metrics, it can help predict menstrual cycles and fertile windows with Cycle Tracking features circular.xyz. This is similar to Oura’s partnership with Natural Cycles, and helps users track periods or potential ovulation more accurately. Circular’s app provides insights into fertility and even menopause, part of an effort to offer more personalized wellness guidance for women gadgetsandwearables.com.

Overall, Circular Ring 2 aims to be a full-spectrum health tracker on your finger. It’s not only capturing the usual fitness stats, but also dipping into medical-grade territory with ECG and tapping into holistic wellness (stress, recovery, women’s health, etc.). Early hands-on reports praise the breadth of data: “In addition to a sleep score… users can view various sleep stages, sleep duration, heart rate variability, fall-asleep and wake-up times, [and] any sleep disturbances,” one reviewer noted tomsguide.com. The key, of course, will be accuracy – something Circular claims to have vastly improved from its first model. The new sensor array and algorithms are said to yield “much more accurate health tracking” (the prior gen was sometimes off by thousands of steps) theverge.com. If those claims hold true in real-world use, Circular 2 will indeed stand among the most advanced ring trackers out there.

Sleep Tracking and Smart Alarm

One of the core uses for smart rings is sleep tracking, and Circular 2 is clearly designed with overnight wear in mind (it’s lightweight and unobtrusive, with no lights or sounds to disturb you). Each night, the ring automatically logs your sleep duration and stages, breaking down how long you spend in Light, Deep, REM sleep, and Awake periods circular.xyz. It produces a Sleep Score (1–100) each morning that incorporates factors like your total sleep time, sleep efficiency (% of time asleep while in bed), consistency of your sleep schedule, and any interruptions.

In the Circular app, you can dig into detailed sleep graphs. For example, the app will chart your heart rate and HRV throughout the night, highlight any elevated heart rate or breathing disturbances, and show the timing of your sleep cycles tomsguide.com. This can help pinpoint issues like frequent awakenings or identify if poor sleep on a given night correlates with late exercise, alcohol intake, high stress day, etc. Circular’s approach here is similar to Oura’s renowned sleep analysis – though one early impression was that Samsung’s sleep tracking offers even more detail, Circular’s presentation is “easy-to-parse” with intuitive graphics tomsguide.com.

A standout feature is the Smart Alarm. Using your nightly data, the ring (via the app) can wake you up at an optimal point in your sleep cycle. You set a desired alarm time or window, and if you’re in a light stage of sleep near that time, the app will trigger an alarm (on your phone) to gently wake you when you’re most likely to feel refreshed circular.xyz. In the first-gen Circular, this smart alarm used the ring’s vibration motor to buzz you silently; in Circular 2, since the vibration motor was removed, the alarm will sound on your phone or connected device. It’s not as silent, but it still beats being jolted out of deep sleep by a loud alarm.

Additionally, Circular’s sleep tracking contributes to your daily Energy Score. Similar to Oura’s Readiness score or Samsung’s Energy metric, it combines your sleep quality with your activity strain from the previous day to gauge how “charged up” you are for the new day tomsguide.com. If you had a short or restless night, your Energy score will be lower, signaling you might need a lighter day or extra rest. Over time, Kira (the AI coach) may give recommendations like adjusting your bedtime or pre-sleep routine if it spots trends (e.g. consistently low recovery scores after late-night workouts or screen time).

In summary, Circular Ring 2 acts like an all-night sleep lab on your finger – tracking biometrics and sleep phases without any effort from you. The data is presented clearly, with actionable insights rather than just raw numbers. And by integrating features like the smart alarm and personalized tips, it doesn’t just tell you how you slept – it actively tries to help you sleep better. As one hands-on reviewer observed after seeing Circular’s sleep and energy reports: “the information is presented in an easy-to-parse manner… Circular also generates a daily Energy Score based on both rest quality and physical activity,” much like its top rivals tomsguide.com tomsguide.com.

Productivity and Lifestyle Tools

Beyond health metrics, the Circular Ring 2 includes a few thoughtful lifestyle features to help you stay on top of your day-to-day wellness and productivity:

• Guided Breathing & Meditation: In moments of stress or when you need better focus, the Circular app offers guided breathing exercises (sometimes called “Coherence” training) circular.xyz circular.xyz. These are short sessions where the app will prompt you to inhale and exhale at a certain pace, often using biofeedback from your heart rate. The goal is to help you reduce stress and increase heart-rate variability by synchronizing your breathing with your heartbeat – leaving you calmer and more clear-headed. Many wearables have breathing apps, but Circular bakes it right into the ring’s core features, so you might get a notification to try a breathing session when your stress levels spike.
• Smart Alerts for Vitals: As mentioned, you can set personalized thresholds for things like heart rate or blood oxygen. If the ring detects, say, your heart rate soaring unexpectedly high while at rest, or your SpO₂ dropping below a set level during sleep, it can trigger a vital alert on your phone circular.xyz. This could be a literal lifesaver in some cases (e.g. flagging an AFib episode, or a possible breathing issue at night). It’s a proactive way to keep you informed of significant changes in your body.
• Medication Reminders: The Circular app includes a simple but useful medication reminder feature circular.xyz. You can input your prescription schedule or supplement routine, and the app will ping you when it’s time to take your dose. This addresses a common adherence problem in a convenient way – since many users will check the app daily for their wellness stats, it’s natural to include health-related reminders there. (Because the ring has no display or vibration now, these reminders appear as phone notifications.)
• “Kira” AI Health Coach: Perhaps one of Circular’s most unique offerings is Kira – an AI-driven personal health coach built into the app circular.xyz circular.xyz. Kira analyzes your collected data (those 140+ biomarkers per day) and provides daily actionable tips. For example, if it notices your sleep quality has been poor and your resting heart rate is trending higher, Kira might suggest an earlier bedtime and a relaxation exercise. If your recovery is good but activity is low, it might encourage a workout. In the first-gen ring, users found Kira to be a bit clunky and slow (it took 14 days to “learn” your baseline), but in Ring 2 Kira has been revamped to calibrate in ~4 days and deliver more timely, accurate advice theverge.com. The idea is to turn all that raw data into a personal action plan – effectively giving you a virtual health consultant on call. This kind of AI coaching is cutting-edge in wearables, and Circular is betting it will set them apart if done right.
• Phone Notifications (Limited): One area where Circular Ring 2 is less focused is general phone notifications. Unlike a smartwatch (or even the original Circular Slim), the new ring will not buzz or light up for every text, call, or app alert – it has no screen and no haptic motor theverge.com. The company intentionally dropped these to prioritize health features. For users, this means Circular 2 is not a mini-smartphone on your finger, and you won’t get distracted by every notification. Some will see this as a pro (fewer interruptions; your ring won’t be lighting up at the dinner table), while others may miss the convenience. Circular’s compromise is that truly important alerts – like the health thresholds or wake-up alarm – will still reach you via your phone. But if you need a wearable for managing texts or meeting alerts, you’d still rely on your phone or consider a smartwatch. Essentially, Circular 2 positions itself as a wellness device first and foremost, not a general notifier.
• Cross-Platform and Integrations: The Circular app works on both iOS and Android, and it’s expected to integrate with popular health platforms. While not explicitly detailed in sources, typically a device like this would sync with Apple Health and Google Fit, allowing you to consolidate your data with other apps. Circular does have a For Professionals portal and data export options on their website, meaning you can share your data with your doctor or other services easily circular.xyz. Contrast this with Samsung’s ring (which is Android-only) – Circular’s cross-compatibility is a big selling point for those who might switch phones or simply want flexibility tomsguide.com.

One could sum it up this way: Circular Ring 2 is designed to quietly slot into your life as a health optimizer. It won’t overload you with distracting features, but it will keep you honest about your habits and help you improve them. As Circular’s CEO Amaury Kosman put it, “This isn’t just a wearable… it’s a statement piece that empowers our users to take control of their wellness without compromising on style.” thenextweb.com The ring’s features reflect that philosophy – sleek, health-driven, and user-centric.

Battery Life and Charging

Battery life has been a critical factor for all wearables, and smart rings need to last long enough that you don’t constantly remove them (especially since many are meant for sleep tracking). The Circular Ring 2 makes significant strides here: battery endurance is roughly 2× the previous model, thanks to a larger battery and more efficient electronics theverge.com.

In real terms, users can expect about 4 days of use per charge in “Performance mode” (where all tracking features – continuous HR, SpO₂, etc. – are enabled) theverge.com. For lighter usage or using a power-saving profile, the ring can stretch up to 7–8 days before needing a recharge theverge.com thenextweb.com. Circular itself touts “up to 8 days” as the max, which matches the claimed battery life of the Oura Ring Generation 4 wareable.com. (It’s worth noting Oura’s 8-day claim is under ideal conditions; in practice many users get around 5–6 days, so if Circular hits 7–8 consistently it’s a real win wareable.com.)

Charging the Circular 2 has also been improved. Instead of the tiny USB plug charger that the first gen used (which was easy to lose and somewhat fiddly), the Ring 2 comes with a dedicated charging dock theverge.com. This likely works similarly to Oura’s charger – you place the ring on a small wireless pad or in a cradle, and it juices up via induction. According to one report, Circular’s new charger is a wireless charging case/dock, making topping up the ring as simple as resting it on your nightstand pad gadgetsandwearables.com. The charging time hasn’t been explicitly stated in our sources, but comparable rings reach full charge in about 60-90 minutes. Even if Circular’s larger battery takes a bit longer, you could easily charge it while showering and getting ready, or use the charging case as a travel companion to boost it on the go tomsguide.com.

One Tom’s Guide editor who tested the Samsung Galaxy Ring (which has a similar battery spec) noted that not having to charge daily was a game-changer: “you won’t need to charge either ring anywhere near as often as your Apple Watch, and could easily go away for a weekend without worrying about packing your charger” tomsguide.com. The same is true for Circular 2 – a multi-day battery means less friction in wearing it 24/7, which is crucial for capturing complete health data.

It’s also impressive given the sensor load (the ECG and continuous SpO₂ could have been battery hogs). Amaury Kosman assured that battery life has doubled from the prior model, and preliminary numbers seem to back that up theverge.com. The inclusion of a Power Save mode offers flexibility: if you don’t need every metric 24/7, you can extend the life to a full week by dialing back frequency of measurements.

All said, Circular Ring 2’s battery life is on par with top competitors – Oura Gen4 is about 6–7 days real-world tomsguide.com, Ultrahuman Ring Air claims 6 days but testers got ~4 days tomsguide.com, and Samsung’s Galaxy Ring is estimated at 5–7 days (varies by ring size) tomsguide.com tomsguide.com. Circular sitting in the upper end of that range while running an ECG sensor is quite an achievement. And by switching to a convenient dock, they removed one of the minor annoyances of the first gen. As one journalist quipped, “Circular is busting out some big battery life numbers. It claims eight days between charges, the same as Oura Ring 4 (although we rarely get Oura past five days).” wareable.com If you’re coming from a smartwatch that you charge every night, using a ring that lasts most of a week will feel downright liberating.

Design, Comfort, and Sizing

One of the first things you notice about the Circular Ring 2 is its design overhaul. The original Circular ring (the “Slim”) had a plastic outer shell that felt cheap – one reviewer said it felt like a 3D-printed prototype on the finger theverge.com. The new model throws that out entirely in favor of a premium metal build. Circular 2 is made of titanium alloy, giving it strength while keeping weight very low circular.xyz. It’s polished and available in four elegant finishes: Matte Black, Silver, Rose Gold, and 24K Gold plating theverge.com. This puts it aesthetically in the same league as Oura’s high-end rings (which also come in gold and stealth black finishes).

The ring’s form factor is a fully enclosed circle – no breaks or gaps – with a slightly domed exterior and a flat inner surface where the sensors and electrodes sit. The inner circumference has two small ECG electrode contacts and the optical sensor array. These sensor bumps protrude just a fraction of a millimeter. Users who tried it on reported that “it felt lightweight and quite comfortable” on the finger, even with those inner bumps tomsguide.com tomsguide.com. At ~2 grams, it’s likely one of the lightest smart rings on the market (for reference, the Oura Ring Gen4 weighs ~3–5 g depending on size tomsguide.com, so Circular is lighter by a gram or two). As a result, most people will forget they’re even wearing it, whether typing, exercising, or sleeping. Waterproofing is also taken care of – the new ring is fully water-resistant (the CEO noted earlier models had some waterproofing issues which have been fixed) theverge.com, so you can shower or swim with it on.

Another big innovation is how you size and purchase the ring. Traditionally, buying a smart ring meant the company ships you a set of plastic sizers first (often for a fee), you try them on to find your best fit, then order the actual ring in that size – a process that can take weeks. Oura and Samsung, for example, charge ~$10 for a sizing kit and create a lot of plastic waste in the process tomsguide.com. Circular Ring 2 disrupts this with its digital ring sizing tool. When ordering, you can use your smartphone camera to measure your finger: you simply place a credit-card-sized object next to your hand as a size reference and snap a photo tomsguide.com tomsguide.com. The app’s AI will instantly calculate your finger dimensions, recommending the exact ring size (e.g. “Size 11”) you need tomsguide.com. In a CES demo, this worked “remarkably well” – the tool gave precise suggestions for each finger tried tomsguide.com tomsguide.com. Circular offers sizes 6 through 13, covering most hands tomsguide.com. This fast, eco-friendly sizing is a game-changer. As Wareable noted, it’s “a really clever idea, and it works… It’s a complete waste of time and plastic to do it the old way” wareable.com wareable.com. By removing that hurdle, Circular potentially removes a major barrier to buying a smart ring (no one likes waiting extra weeks just to know their size).

In terms of style, the Circular 2 has a minimalist, unisex look. There are no logos visible on the outside. It essentially looks like a stylish modern ring – especially in the gold or rose gold, it could pass for a piece of jewelry. This is intentional: the CEO said they wanted it to be not just functional but something that “doesn’t compromise on style” thenextweb.com. Unlike a bulky smartwatch, a sleek ring can blend with any outfit. You could wear it to a wedding or board meeting and no one would guess it’s a health tracker. For those who want their wearable to be discreet, Circular fits the bill.

One more subtle improvement: Circular Ring 2 now comes with a durable scratch-resistant coating on the titanium (the first gen had issues with scuffing). The company had even updated the old Slim units with a scratch-resistant coating as a stopgap wareable.com. With titanium and possibly a DLC (diamond-like carbon) or tungsten-carbide coating (common on Ultrahuman’s ring ultrahuman.com ultrahuman.com), the Circular 2 should hold up to daily wear without turning into a scratched eyesore.

Finally, it’s worth noting Circular resolved a patent dispute with Oura – so the design moving forward is unencumbered. Oura had sued Circular for patent infringement in the past (leading to a royalty agreement thenextweb.com), but now that’s behind them wareable.com. The “luxurious” redesign and the emphasis on accuracy signal that Circular wants to stand toe-to-toe with Oura, Ultrahuman, and Samsung’s upcoming ring in terms of both looks and performance wareable.com. From what we’ve seen, Circular Ring 2 certainly looks the part of a flagship smart ring for 2025.

Price, Subscription, and Value

The Circular Ring 2 is priced in the premium smart ring tier. Its retail price is about $349 to $379 USD (approximately €349 in Europe) depending on finish/color dataconomy.com forbes.com. Early backers on Kickstarter got sizeable discounts (up to 57% off during pre-order circular.xyz), but those deals were limited. At ~$349, Circular 2 is directly competing on price with the Oura Ring (Gen4 starts at $349 as well tomsguide.com) and with the Ultrahuman Ring Air ($349). Samsung’s Galaxy Ring is expected to come in a bit higher around $399 tomsguide.com.

Where Circular really differentiates on value is the lack of subscription fees. Once you buy the ring, all its features and the full app insights are included for life. Oura, by contrast, requires a $5.99/month membership (or $72/year) to access most of the detailed metrics and insights beyond a basic level tomsguide.com tomsguide.com. Over a couple of years, that subscription can make Oura considerably more expensive. Ultrahuman and most other newer entrants have followed a no-subscription model as well, so Circular is competitive in that respect. It’s refreshing that you get “13+ features, no subscription” out of the box, as the company touts circular.xyz.

For the price, you are getting a device with some capabilities that even more expensive wearables don’t have – chiefly the ECG. It’s notable that top-of-the-line smartwatches with ECG (like the Apple Watch or Galaxy Watch) also cost $300–$400 and still charge no monthly fee; so Circular’s pricing is in line with other advanced health wearables.

Included in the purchase, you get the ring itself, the charging dock, and access to the Circular app and all updates. Circular has promised OTA (over-the-air) updates bringing new features over time circular.xyz. In fact, they’ve already announced that blood pressure and glucose trend tracking features are in development for the ring, targeted to release by end of 2025 gadgetsandwearables.com. If those materialize (even as non-invasive estimates), it would add huge value to existing devices at no extra cost. The company’s strategy seems to be one-time device revenue, but then continuously improving the product through software – meaning early adopters could actually see their ring getting more capable over time. There are no guarantees these experimental features (BP or glucose trends) will work, but the prospect highlights how Circular is positioning the ring as a long-term health gadget, not something you upgrade annually.

When evaluating Circular Ring 2’s value, consider:

Pros (Value Adds): No recurring fees; includes rare features like ECG/AFib detection that normally might come at a premium; cross-platform support (no ecosystem lock-in); free AI coaching that some might pay extra for in other apps; and a premium build equivalent to jewelry. If you were interested in an Oura but balked at the subscription, Circular gives you an alternative. As an early user, you’d also be getting into a platform that’s actively expanding (with new metrics promised).

Cons (Cost/Risk): At $349+, it’s an expensive piece of tech jewelry. The company Circular is a startup, not an established giant, so some buyers might worry about long-term support or warranty service (though the successful crowdfunding and version 2.0 improvements inspire confidence). Also, if one of your main desires is smartphone notifications on your finger, note that Circular 2 doesn’t really fulfill that – a $200 smartwatch might serve that purpose better. Essentially, you’re paying a premium specifically for health tracking in a tiny form factor.

In the grand scheme, Circular Ring 2 is priced similarly to its closest competitors, but aims to offer more bang for your buck in features and freedom from subscriptions. As The Next Web succinctly put it: “Starting price of $380… that’s a bit pricier than the Oura Ring 4 ($349). However, unlike Oura’s, the Circular ring is available subscription-free.” thenextweb.com In other words, you pay slightly more upfront, but potentially save a lot over the life of the product while getting even broader functionality.

Real-World User Experience and Early Reviews

Given that the Circular Ring 2 only began shipping in mid-2025, widespread user reviews are still rolling in. However, we can glean a sense of the experience from tech experts who previewed the ring and the improvements it brings:

• Massive Improvement over Gen1: Virtually everyone agrees Circular 2 is a night-and-day leap from the first Circular ring. Where the original was criticized for poor accuracy, short battery (2 days), slow syncing, and cheap feel theverge.com yahoo.com, the new model tackles each of those. “On paper, it seems like Circular has taken the laundry list of issues with the Slim and ticked them off one by one,” writes The Verge theverge.com. The switch to titanium and a proper manufacturing process means no more 3D-printed vibe. Background syncing now works seamlessly, according to the CEO, so you shouldn’t have to manually force data transfers – a big relief theverge.com. The ring is also now fully waterproof, and connectivity issues have been ironed out theverge.com. Essentially, if you tried (or read about) the flawed first-gen, know that Circular 2 is a complete reboot. In the words of Circular’s cofounder, “The Ring 2 isn’t just an upgrade — it’s a complete revamp, and to be honest, it had to be.” reddit.com
• Accuracy and Trustworthiness: A key part of user experience is whether you trust the data. Circular’s team emphasized accuracy as a pillar of the redesign. The upgraded PPG sensors (it now has multiple LEDs and detectors) aim to fix issues like step counts being wildly off. One reviewer who had tested the Slim noted it was sometimes “off by 5,000 steps” in a day theverge.com, which is obviously unacceptable. The Circular 2’s sensor array is said to be much more in line with reality – we’ll have to see independent tests, but the addition of an ECG (which can help validate heart rate readings) and more advanced algorithms are promising. FDA clearance for the AFib feature also adds credibility; it suggests the heart data meets a certain standard of clinical accuracy for that purpose wareable.com. Early impressions from CES were positive, but final judgment will come from in-depth reviews once units are in the field (likely late 2025).
• App Experience: The companion app is getting a makeover to match the new hardware. Users of gen1 often complained the app was clunky and Kira’s insights weren’t very useful. Circular has streamlined the interface, aiming to present a holistic view akin to Oura’s highly-praised app tomsguide.com. For example, sleep and activity are correlated to produce that Energy score; the interface uses clear color-coded charts. Tom’s Guide noted that while Circular’s data might not be quite as granular as Samsung’s (which even scores things like body circadian rhythm in detail), it’s plenty detailed for most and “presented in an easy-to-read way” tomsguide.com. The fact that Kira’s advice is now faster and more “accurate and complex” thanks to algorithm improvements is encouraging theverge.com. If the app can approach the polish of Oura’s, users will be in for a good experience. One thing to look out for: initial calibration. Circular says Kira only needs ~4 days to learn your baseline theverge.com, but in general, any device might take a couple weeks for all its metrics (like HRV baselines, etc.) to stabilize. Early users should allow a bit of break-in period and not panic if the first day’s scores seem off.
• Daily Comfort and Wear: So far, comfort seems to be a non-issue. Testers wore it at CES and commented on how lightweight it is tomsguide.com. The inner sensor bump – also present in Oura and Ultrahuman rings – might feel odd for a day or two if you’re new to rings, but most adapt quickly and it helps keep the ring in place. The absence of any lights (the LEDs are infrared or very low-key) means no distraction at night; you can sleep with it without noticing it. Because Circular 2 is robustly waterproof (rated for at least 50m, likely, given others go 100m) ultrahuman.com, you don’t have to constantly remove it. This is a big plus for user experience – the less you remove it, the less likely you are to forget it somewhere or break the habit of wearing it.
• Support and Updates: A potential consideration for experience is how the company engages post-launch. Circular delivered the product roughly on schedule to its backers gadgetsandwearables.com, which builds some trust. They also have been transparent about upcoming features like blood pressure and glucose trend analysis, which shows they have a roadmap. If they roll out those features and maybe bring back some form of haptic feedback in a future variant (they hinted at possibly a separate line for haptics in the future theverge.com), it will keep users invested. On the flip side, as an early adopter device, some firmware updates may be needed to iron out any remaining bugs. Buyers should be prepared for occasional app updates or ring firmware flashes as the kinks are worked out – which is normal in this space.

So far, expert sentiment is optimistic. The Verge’s wearable tech reporter (who admittedly was burned by the first Circular) expressed cautious hope, saying Circular 2 addressing all those issues is “certainly a tall order… But if it can, that’d be one hell of a redemption arc.” theverge.com. Tom’s Guide named it “the most impressive smart ring at CES 2025” and implied it could finally push smart rings into the mainstream by removing friction points tomsguide.com tomsguide.com. Perhaps the words of Wareable sum it up: “It’s good to see [Circular] challenging the big guns of the smart ring world again… adding ECG is a strong message that it means business for 2025.” wareable.com. Real users will soon confirm if Circular Ring 2 truly lives up to the hype, but all signs indicate it’s a strong contender in the growing smart ring arena.

How Circular Ring 2 Stacks Up Against Other Smart Rings

Smart rings are increasingly popular, and Circular 2 isn’t entering a vacuum. It’s up against both established players like Oura and a wave of newcomers (and upcoming devices) from tech companies and startups. Below, we’ll compare Circular Ring 2 with some of the prominent smart rings currently on the market or coming soon: the Oura Ring (Gen 3/Gen 4), the Ultrahuman Ring Air, and the Samsung Galaxy Ring. We’ll also briefly mention other notable rings (like Movano’s Evie and Amazfit’s Helio) to complete the picture. Each has its unique strengths and focus areas.

First, here’s a quick comparison table of major metrics:

(Table sources: Circular price and no-sub thenextweb.com, battery theverge.com thenextweb.com; Oura price/sub tomsguide.com, battery tomsguide.com; Ultrahuman price tomsguide.com, battery tomsguide.com, features ultrahuman.com ultrahuman.com; Samsung price/battery tomsguide.com tomsguide.com, platform tomsguide.com.)

As the table highlights, Circular Ring 2, Oura, Ultrahuman, and Samsung’s ring all fall in a similar price bracket and offer broadly comparable core functionality (24/7 health and sleep tracking). But each has unique aspects worth expanding on:

Oura Ring: Often considered the gold standard of smart rings, Oura (especially the latest Gen 3/Gen 4) has a proven track record. It shines in sleep tracking accuracy and refined insights – Oura’s Sleep and Readiness scores are widely trusted, and it’s been used in research studies. Oura also has a slick app and features like guided audio sessions for meditation, etc. The Gen4 Oura (released late 2024) made the ring lighter (3.3–5.2g) tomsguide.com and improved battery life slightly, plus introduced new colors. However, it lacks an ECG or blood pressure capability – Oura has stuck to optical sensors only. It also doesn’t attempt on-device notifications or fancy gestures; it’s a wellness ring through-and-through. The biggest downside is the subscription: without paying monthly, Oura owners miss out on detailed trends and insights (you’d only get basic daily scores). This has been a sore point for some users and where competitors aim to undercut Oura. In terms of platform, Oura is platform-agnostic (works with Android or iPhone) and it plays well with Apple Health, Google Fit, and even has an API for third parties. So if you use other fitness apps or an Apple Watch, Oura can integrate those data points. Circular 2 vs Oura: Circular offers more health metrics (ECG) and no fees, while Oura offers a slightly more mature ecosystem and brand pedigree. Notably, Oura has an edge in women’s health right now thanks to its partnership with Natural Cycles – it’s FDA-cleared for birth control when used with that app. Circular and Ultrahuman are close behind with cycle tracking, but Oura’s head start and validation there is worth considering for female users.

Ultrahuman Ring Air: Ultrahuman is a fitness startup from India that entered the ring space to complement its metabolic health platform. The Ring Air (launched 2023) focuses a lot on metabolic fitness and stress. It measures the usual vitals and gives scores for recovery, but one unique angle is how it can integrate with Ultrahuman’s continuous glucose monitoring (CGM) program. If a user also uses Ultrahuman’s glucose sensor, the app can overlay heart rate, sleep, and glucose levels together, giving rich insight into how your body responds to food and exercise. The Ring Air also offers some novel features: for example, “Caffeine window” detection – it can analyze your circadian rhythm and suggest ideal times to have (or cut off) caffeine so as not to disrupt sleep ultrahuman.com ultrahuman.com. It introduced a feature for overnight AFib detection but via an external PowerPlug – from the Ultrahuman site, this appears to be a small under-mattress or bedside device you keep near you at night, which can pick up more precise heart rhythm data (possibly via bioimpedance) to detect AFib, with a subscription around $4/month for that service wareable.com ultrahuman.com. So Ultrahuman does technically offer AFib alerts, but Circular 2 does it more directly on the ring itself and without extra cost. Ultrahuman’s ring is slightly heavier (up to 3.6g) but still very light, and it’s made of a titanium with a tungsten carbide coating, similar durability to Circular. One limitation is that Ultrahuman launched initially with only a black color, though they now have five finishes including gold and silver tomsguide.com tomsguide.com. Battery life is comparable, though reviews suggest it might not last the full 6 days in practice, especially if you use features like frequent HR broadcasting. Ultrahuman is also subscription-free for basic use, which combined with its metabolic focus can make it attractive to biohackers and fitness enthusiasts. If you are big into tracking your diet’s effect on your body, Ultrahuman has an edge. If you want a more medical-grade heart monitor and polished app, Circular or Oura might appeal more.

Samsung Galaxy Ring: This is the big-tech entrant that many have been waiting for. Samsung’s Galaxy Ring (expected late 2024 or 2025) is significant because it’s the first smart ring from a top smartphone/watch maker, signaling mainstream validation of the category. The Galaxy Ring is expected to pack all the core health sensors (heart rate, SpO₂, temperature) and feed that data into the well-established Samsung Health app tomsguide.com. Samsung Health already tracks workouts, sleep, stress (on Galaxy watches) and provides coaching programs – the ring will extend that ecosystem. One of Samsung’s unique ideas is using AI to generate health insights, likely leveraging data from both the ring and other devices. For instance, Samsung has hinted that if you wear a Galaxy Watch and the Ring together, the ring’s battery lasts longer (because tasks can be shared) and the combo yields more comprehensive readings tomsguide.com tomsguide.com. They even allow the watch and ring to work in concert for features like fall detection or advanced workout tracking. Another novel feature: the Galaxy Ring reportedly supports a “double-pinch” gesture, meaning you can control functions (possibly like pausing music or snapping a photo) by tapping your thumb and index finger together twice while wearing the ring tomsguide.com. This is an extension of assistive tech (similar to gestures on Apple Watch or Google’s gesture control) and could hint at future control schemes. Where Samsung Ring falls short is it doesn’t include an ECG (Samsung likely left ECG to their watches, which are already FDA-cleared for it). Also, crucially, the Galaxy Ring will be incompatible with iPhones – it’s built for the Android/Samsung ecosystem only tomsguide.com. So roughly half the smartphone market (iOS users) can’t use it, which actually benefits companies like Circular and Oura who welcome all users. Price-wise, at $399 the Galaxy Ring is priciest of the bunch, but Samsung isn’t charging a monthly fee, and they might bundle it with phone promotions. Samsung’s ring could become the best choice for dedicated Samsung Galaxy users who want seamless integration and don’t mind the closed ecosystem. But if you ever leave Android, that ring becomes a paperweight, whereas Circular/Oura/Ultrahuman can move with you.

Other Notable Smart Rings:

• Movano Evie Ring: A newcomer focusing on women’s health, the Evie Ring is designed by Movano and launched in late 2023 at $269 (no subscription) eviering.com. It aims to be FDA-cleared as a medical device and puts special emphasis on menstrual cycle tracking, ovulation prediction, and even menopausal symptom tracking. It also measures heart rate, SpO₂, and has a stylish design targeted at female users. Evie doesn’t have ECG, but it’s carving a niche as the first women-specific smart ring. This could be an alternative for users who want something a bit more affordable and tailored to female wellness. However, it’s relatively new and its app and ecosystem are still growing. Circular’s new women’s suite shows that mainstream rings are catching up in that area.
• Amazfit Helio Smart Ring: From Zepp Health (makers of Amazfit watches), the Helio Ring launched in May 2024, priced around $299 (now dropped to $199) tomsguide.com androidauthority.com. It’s marketed towards athletes and fitness folks, boasting accurate heart rate, SpO₂, stress tracking, and a companion fitness app. The Helio differentiates itself by often being sold bundled with an Amazfit smartwatch for those who want both. It also includes a charging case that can provide an impressive total runtime (some reports say the case allows up to 7 weeks of use by recharging the ring on the go) 9to5google.com. At $199 (current price), it undercuts others, making it one of the more affordable full-featured rings. No subscription needed. Downside: it might not be as polished as Oura/Circular in insights, and it’s early in its software life. But for budget-conscious buyers, Helio is one to watch.
• RingConn and Other Budget Rings: RingConn is a lesser-known brand that came via crowdfunding. Their RingConn Gen 2 Air is a budget smart ring (~$150–$200) that covers basics like HR, sleep, steps. TechAdvisor and others have noted it “beats Oura in some ways” like price and battery (it reportedly can last up to 10–14 days!) techadvisor.com. However, the app and accuracy might not match the big players. If one’s priority is simply a cheap sleep tracker, devices like RingConn or even generic ones from brands like Go2Sleep exist. But you get what you pay for – the experience and support won’t rival Circular or Oura.

In comparing Circular Ring 2 vs its rivals: Circular holds some unique cards (ECG, AI coach, digital sizing) and aligns closely with Ultrahuman and Oura on being subscription-free (Oura being the exception here). Samsung’s ring will have the muscle of a huge company but comes with platform lock and a higher price. For a prospective buyer, the decision might come down to priorities:

• If you want the most validated, polished platform and don’t mind a monthly fee: Oura Ring is a safe bet, with years of refinements and a large user community.
• If you want maximum health data and cutting-edge features with no subscription: Circular Ring 2 is extremely appealing, offering medical-grade metrics (ECG) that others lack.
• If you’re very fitness/metabolic-focused and maybe use a glucose monitor or want stress/cycle insights without paying Oura, Ultrahuman Ring Air is a strong contender.
• If you’re an Android user deep in the Samsung ecosystem: holding out for the Galaxy Ring could make sense, especially if you already use Samsung Health and a Galaxy Watch.
• If cost is a big factor, consider the likes of Helio Ring (if $199 pricing continues) or the Movano Evie for a slightly cheaper device without recurring costs.

The smart ring space in 2025 is vibrant, with “increasing competition in the smart ring space” as The Verge noted theverge.com. This competition is great for consumers: it pushes each company to innovate and address weaknesses. Circular, for example, clearly stepped up its game in response to Oura and others – and even Oura might be feeling the pressure, as they reportedly signed a deal to get royalties from Circular’s US sales as part of a patent settlement thenextweb.com. Ultimately, each ring has its “personality”: Circular is positioning as the tech-forward health companion, Oura as the lifestyle wellness guru, Ultrahuman as the fitness biohacker’s tool, and Samsung as the convenient all-in-one (if you own their stuff).

Conclusion

The Circular Ring 2 arrives at a pivotal time for wearables. Consumers are looking beyond traditional wrist trackers for something that blends seamlessly into daily life. With its blend of elegant design and powerhouse health tech, Circular 2 makes a compelling case as one of the most advanced smart rings you can buy today. It packs serious capabilities – from ECG-based heart monitoring to a sophisticated AI wellness coach – into a tiny form factor that you’ll barely notice on your finger. By learning from its first attempt, Circular has addressed past pitfalls (accuracy, battery, build quality) and boldly differentiated itself with features like digital sizing and a subscription-free platform.

Experts are already taking notice, with some saying Circular 2 could be the device that brings smart rings into the mainstream in 2025 tomsguide.com. Of course, it faces stiff competition. Oura remains the incumbent favorite for many, Samsung’s entry will grab headlines, and other niche rings offer their own twists. But Circular seems ready for the challenge – as Wareable’s editor observed, the company is “back on track… challenging the big guns of the smart ring world again” wareable.com.

For tech-savvy consumers and health enthusiasts, the Circular Ring 2’s proposition is hard to ignore: no recurring fees, actionable health insights, and potentially life-saving tech like AFib alerts in a stylish ring that works with any smartphone. It represents how far the wearable industry has come – miniaturizing advanced sensors from bulky watches down to ring-size, without sacrificing too much battery or accuracy.

In summary, if you’re considering joining the smart ring revolution, the Circular Ring 2 deserves a top spot on your list. It combines many of the best aspects of its competitors while adding its own innovations to the mix. As with any new gadget, it will require real-world validation and user feedback over time. But if the initial impressions hold true, the Circular Ring 2 isn’t just an incremental update – it’s a statement that smart rings have truly arrived as versatile, everyday health companions. And in this wearable showdown, that ring on your finger might just end up being the smartest device you own.

Sources:

• Circular Official Site – “Circular Ring 2: Your Personal Health Companion” circular.xyz circular.xyz
• The Verge – V. Song, “Circular Ring 2 adds FDA-cleared EKGs, better battery life, and a more premium design.” (CES 2025 coverage) theverge.com theverge.com
• Tom’s Guide – D. Bracaglia, “Hands-on with Circular Ring 2 — most impressive smart ring at CES 2025” tomsguide.com tomsguide.com
• Wareable – J. Stables, “Circular Ring 2: Hands on with the ECG smart ring” wareable.com wareable.com
• The Next Web – S. Geschwindt, “Circular seeks redemption with new smart ring that could outshine Oura” thenextweb.com thenextweb.com
• Gadgets & Wearables – M. Maslakovic, “Circular Ring 2 with ECG, wireless charging: Now shipping” gadgetsandwearables.com gadgetsandwearables.com
• Tom’s Guide – J. McGuire, “Oura Ring vs Ultrahuman Ring Air – which should you buy?” (Oct 2024) tomsguide.com tomsguide.com
• Tom’s Guide – K. Kozuch, “I wore the Samsung Galaxy Ring for one week…” (July 2024) tomsguide.com tomsguide.com