Oura
Oura Ring 4
$349Cheaper
Released 2024-10
Best Smart Rings · head-to-head
Oura Ring 4 vs Circular Ring 2
A sourced, side-by-side comparison. Oura Ring 4 is cheaper at $349. Every spec and price links to its source.
Circular
Circular Ring 2
$379
Released 2025-08
Which is better: the Oura Ring 4 or Circular Ring 2?
On the specs we track, they're closely matched. The Oura Ring 4 is the cheaper at $349.
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Oura Ring 4 | Circular Ring 2 |
|---|---|---|
| US price | $349 | $379 |
| Brand | Oura | Circular |
| Released | 2024-10 | 2025-08 |
| Material | Titanium (non-allergenic inner and outer surfaces) | Titanium (PVD coating on premium finishes) |
| Weight (g) | 3.3-5.2 | 3 |
| Battery days | 8 | 8 |
| Spo2 | Yes | Yes |
| Temperature sensor | Yes | Yes |
| Ecg | No | Yes |
| Subscription required | Yes | No |
| Water resistance (m) | 100 | — |
Sources — Oura Ring 4: ouraring.com (verified 2026-06-15). Circular Ring 2: shop.circular.xyz (verified 2026-06-15).
What's the difference between the Oura Ring 4 and Circular Ring 2?
Where the two actually differ on the specs we track (4 of 8). Matching specs are omitted.
- Material: Oura Ring 4 Titanium (non-allergenic inner and outer surfaces) vs Circular Ring 2 Titanium (PVD coating on premium finishes)
- Weight (g): Oura Ring 4 3.3-5.2 vs Circular Ring 2 3
- Ecg: Oura Ring 4 false vs Circular Ring 2 true
- Subscription required: Oura Ring 4 true vs Circular Ring 2 false
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Oura Ring 4
Four testers (Tom's Guide, TechRadar, Engadget, Digital Trends) all hands-on-tested the Oura Ring 4 and call it the best smart ring you can buy, praising the all-titanium comfort and companion app. Every source flags the mandatory ~$5.99/month subscription; easy scratching and step/calorie/activity-detection accuracy are the recurring doubts across reviews. (4 sourced reviews, 4 lab-tested.)
Praised: Comfortable all-titanium design with flush, recessed sensors; Excellent companion app with clear data presentation; Long real-world battery life (roughly 5.5-7 days per charge).
Flagged: Mandatory ~$5.99/month subscription to unlock most features; Step / calorie / activity-detection accuracy lags a smartwatch; Titanium surface scratches easily within weeks.
Circular Ring 2
No sourced tester review yet.