Smart Rings / Circular Ring 2 (2025) vs Oura Ring 4 (2024)
Circular Ring 2 (2025) vs Oura Ring 4 (2024)
Oura Ring 4 (2024)
The widest size range Oura sells, now heavily discounted — same subscription, though.
Wins overall by 0.3 points
Quick Verdict
The Oura Ring 4 (2024) wins by 0.3 points, which is not enough to settle it. The only FDA-cleared AFib ring — attached to the buggiest app in the category. Pick on the specs that matter to you, not the overall score.
The Circular Ring 2 (2025) and Oura Ring 4 (2024) are both closely matched smart Ring models, and the Oura Ring 4 (2024) is $50 cheaper than the Circular Ring 2 (2025) ($249 vs $299). On Subscription Freedom, the Circular Ring 2 (2025) leads (8.0 vs 2.0/10) — how much of the ring keeps working with no recurring payment — the category's defining trap. On App & Data, the Oura Ring 4 (2024) leads (9.0 vs 4.5/10) — app stability, insight depth, platform parity and whether you can get your history out. On Sleep Tracking, the Oura Ring 4 (2024) leads (9.3 vs 7.0/10) — sleep staging depth, overnight accuracy and how usable the morning report is. Overall, the Oura Ring 4 (2024) scores 7.4/10 across our 8 scoring categories versus 7.1/10 for the Circular Ring 2 (2025), though the gap is close enough that your specific use case should decide it. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Circular Ring 2 (2025) | Oura Ring 4 (2024) |
|---|---|---|
| Price | $299.00 | $249.00 |
| Release Year | 2025 | 2024 |
| Battery Life (claimed) (days) | 8 | 8 |
| Battery, In Practice | Circular publishes two numbers, not one: 8 days in power mode and 5 days in performance mode — performance mode is the one that samples more often. Tom's Guide's tester got a week or more in practice. | Oura publishes 5-8 days and states outright that it varies with ring size, app settings and activity level. Smaller sizes are nearer 5. Charging takes 20-80 minutes depending on how flat it is. |
| Subscription | No mandatory subscription today; core features come with the ring, and some advanced screens are unlocked with in-app coins earned by wearing it. Circular has said a premium tier covering blood glucose and blood pressure is coming, with neither price nor date published — so the no-subscription position is provisional, not guaranteed. | Required in practice. $5.99/month or $69.99/year after one free month, on exactly the same terms as the Ring 5 — the membership is per account, not per ring, so upgrading later does not cost a second subscription. |
| 3-Year Cost of Ownership ($) | 299✓ | 458.97 |
| Sizes Offered | US 6-14 | US 4-15, no half sizes — the broadest range here, and the reason to buy the older generation if your finger is very small or very large |
| Sizing Kit | Two routes: a camera-and-credit-card digital sizing flow that needs no kit at all, or a $5 physical replica-ring kit. This is the only brand here that lets you skip the kit wait entirely. | Free plastic sizing kit ships before the ring; wear the sizer at least 24 hours including overnight. Budget about a week before the real ring is ordered. |
| Returns & Size Exchange | 14-day no-questions-asked return policy, 1-year warranty (2 years in the EU). | Oura does not publish a return window on its warranty page. The 1-year limited warranty excludes scratches, dents and batteries, and secondhand purchases from unauthorised resellers are not covered at all. |
| Measured vs Inferred | The only ring in this comparison with actual ECG electrodes: a 40-second single-lead reading screened for atrial fibrillation. Everything else — the 140+ 'biosignals' across 13+ health features — is derived from the same PPG, temperature and motion stack every other ring uses. | Green plus infrared LEDs for continuous heart rate and HRV, red plus infrared for blood oxygen reported overnight rather than continuously, an NTC skin-temperature sensor and an accelerometer. Readiness, Stress and Resilience are derived scores on top of those signals. |
| FDA Clearance | Circular states, and Tom's Guide's review confirms, that the ring is FDA-cleared to monitor for irregular heartbeats indicating AFib. That clearance covers the AFib feature, not the other 140 biosignals. | None published. Oura markets the ring and app as general wellness, not as a medical device. |
| Water Rating | Sources conflict: Circular's own store page lists IP68 only, while Tom's Guide's review states 50m water resistance with IP68 — either way, half the 100m rating Oura and RingConn claim | Water resistant to 100m/328ft |
| Phone Support | iOS and Android | iOS and Android, full feature parity |
| Charger & Data Export | Proprietary charger. Export: not published by the manufacturer. Tom's Guide reported sync failures that lost whole nights of sleep data, so what reaches the app is not always complete. | Proprietary size-specific dock plus USB-C cable in the box; the Ring 5 charger is a different part. Export: not published as a one-click history download; Oura documents a personal-access-token Cloud API. |
| Warranty | 12 months | 12 months |
| Colors | Obsidian Black, Silver, Gold, Rose Gold | Silver, Black, Brushed Silver, Stealth, Gold, Rose Gold |
Category Scores
Subscription Freedom
The Circular Ring 2 (2025) leads clearly here, 8.0 against 2.0 — a 6.0-point margin on how much of the ring keeps working with no recurring payment — the category's defining trap. If that is what you are buying for, the Oura Ring 4 (2024) does not close the gap elsewhere.
Sleep Tracking
The Oura Ring 4 (2024) leads clearly here, 9.3 against 7.0 — a 2.3-point margin on sleep staging depth, overnight accuracy and how usable the morning report is. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Health Sensing
The Circular Ring 2 (2025) is marginally ahead, 8.5 to 8.2. A gap this small rarely decides a purchase on its own, though it counts if what the sensors genuinely measure — heart rate, SpO2, temperature, ECG — rather than infer is your priority.
Battery Life
The Circular Ring 2 (2025) leads clearly here, 8.0 against 7.0 — a 1.0-point margin on real days between charges with continuous sensing on, plus what the charging case adds. If that is what you are buying for, the Oura Ring 4 (2024) does not close the gap elsewhere.
Sizing & Fit
The Oura Ring 4 (2024) leads clearly here, 8.5 against 8.0 — a 0.5-point margin on how many sizes exist, how good the sizing kit is, and how forgiving the exchange policy is. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
App & Data
The Oura Ring 4 (2024) leads clearly here, 9.0 against 4.5 — a 4.5-point margin on app stability, insight depth, platform parity and whether you can get your history out. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Durability
The Oura Ring 4 (2024) leads clearly here, 7.5 against 5.5 — a 2.0-point margin on finish scratch resistance, water rating in practice, and whether the finish is warrantied. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Value
The Oura Ring 4 (2024) leads clearly here, 7.5 against 7.0 — a 0.5-point margin on what the ring delivers against its total cost of ownership, not just its sticker price. If that is what you are buying for, the Circular Ring 2 (2025) does not close the gap elsewhere.
Best For
Choose the Circular Ring 2 (2025) if…
- • Subscription Freedom matters most to you — the Circular Ring 2 (2025) scores 8.0/10 here (how much of the ring keeps working with no recurring payment — the category's defining trap).
- • Battery Life matters most to you — the Circular Ring 2 (2025) scores 8.0/10 here (real days between charges with continuous sensing on, plus what the charging case adds).
- • Your main use case is no-subscription or heart-health.
Choose the Oura Ring 4 (2024) if…
- • App & Data matters most to you — the Oura Ring 4 (2024) scores 9.0/10 here (app stability, insight depth, platform parity and whether you can get your history out).
- • Sleep Tracking matters most to you — the Oura Ring 4 (2024) scores 9.3/10 here (sleep staging depth, overnight accuracy and how usable the morning report is).
- • Durability matters most to you — the Oura Ring 4 (2024) scores 7.5/10 here (finish scratch resistance, water rating in practice, and whether the finish is warrantied).
- • You want to spend less — it's $50 cheaper.
- • Your main use case is womens-health.
Pros & Cons
Circular Ring 2 (2025)
Pros
- +The only ring here with real ECG electrodes and an FDA clearance for AFib detection
- +Digital sizing by phone camera removes the one-to-two-week sizing-kit wait every rival imposes
- +$299 with no mandatory subscription, against $608.97 over three years for a base Oura Ring 5
- +Advanced screens are earned by wearing the ring rather than billed monthly
Cons
- −The app is the weak link: Tom's Guide hit sync failures that lost sleep reports outright, and could not get the ECG feature to run during testing
- −Circular has announced a future premium tier for glucose and blood pressure with no price or date, so the no-subscription promise is not locked in
- −Water rating is half the category norm, and sources disagree on whether it is 50m or IP68-only
- −Titanium finish was described as scratch-prone, and the interior sensors protrude enough to leave marks on the finger
- −Fitness tracking is thin next to Samsung and Oura — this ring is aimed at cardiac screening, not training
Oura Ring 4 (2024)
Pros
- +Sizes 4 to 15 — if the Ring 5's 6-13 window excludes you, this is the Oura that fits
- +Now routinely $249 in silver or black, $100 under its own list price, for sensing that is a generation behind at most
- +Recessed sensors mean no protruding domes pressing into the finger, unlike the Circular Ring 2
- +Same app, same membership, same iOS/Android parity as the Ring 5
Cons
- −The $5.99/month membership still applies, so three years costs $458.97 even at the discounted hardware price
- −Noticeably chunkier than the Ring 5 — that is the whole reason the Ring 5 exists
- −Discounted stock is concentrated in Silver and Black; Gold and Rose Gold still list at $499
- −Warranty covers manufacturing defects only, not the scratches titanium picks up in normal wear
- −Amazon listings are per size and per colour, so the ASIN you click must match the size you actually need
Shop by Need
FAQs
Is the Circular Ring 2 (2025) or Oura Ring 4 (2024) better overall?+
Based on our 8-category scoring, the Oura Ring 4 (2024) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Subscription Freedom, the Circular Ring 2 (2025) or the Oura Ring 4 (2024)?+
The Circular Ring 2 (2025) scores higher on Subscription Freedom (8.0/10 vs 2.0/10) — how much of the ring keeps working with no recurring payment — the category's defining trap.
Which is better for App & Data, the Circular Ring 2 (2025) or the Oura Ring 4 (2024)?+
The Oura Ring 4 (2024) scores higher on App & Data (9.0/10 vs 4.5/10) — app stability, insight depth, platform parity and whether you can get your history out.
Which is better for Sleep Tracking, the Circular Ring 2 (2025) or the Oura Ring 4 (2024)?+
The Oura Ring 4 (2024) scores higher on Sleep Tracking (9.3/10 vs 7.0/10) — sleep staging depth, overnight accuracy and how usable the morning report is.
Which is better for Durability, the Circular Ring 2 (2025) or the Oura Ring 4 (2024)?+
The Oura Ring 4 (2024) scores higher on Durability (7.5/10 vs 5.5/10) — finish scratch resistance, water rating in practice, and whether the finish is warrantied.
Is the Circular Ring 2 (2025) worth the price difference over the Oura Ring 4 (2024)?+
The Oura Ring 4 (2024) is the cheaper option at $249 versus $299. Whether the pricier model is "worth it" depends on how much you value its lead in Subscription Freedom.
Which is better suited to my use case?+
The Circular Ring 2 (2025) is the better fit if you mainly care about no-subscription or heart-health. The Oura Ring 4 (2024) is the better fit for womens-health.
What's the warranty on the Circular Ring 2 (2025) vs the Oura Ring 4 (2024)?+
The Circular Ring 2 (2025) ships with a 12-month warranty; the Oura Ring 4 (2024) ships with a 12-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
RingConn Gen 2 (2024) — $269.00
Premium Option
Samsung Galaxy Ring (2024) — $299.99
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.