Oura
Oura Ring 4
$349
Released 2024-10
Best Fitness Trackers · head-to-head
Oura Ring 4 vs Xiaomi Smart Band 9
A sourced, side-by-side comparison. Oura Ring 4 is cheaper at $349. Every spec and price links to its source.
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Xiaomi
Xiaomi Smart Band 9
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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 | Xiaomi Smart Band 9 |
|---|---|---|
| US price | $349 | — |
| Brand | Oura | Xiaomi |
| Released | 2024-10 | — |
| Form factor | ring | band |
| Display | — | AMOLED 1.62in |
| Battery days | 8 | 21 |
| Gps | No | No |
| Spo2 | Yes | Yes |
| Ecg | No | No |
| Subscription required | Yes | No |
| Water resistance (m) | 100 | 50 |
| Release | 2024 | — |
Sources — Oura Ring 4: support.ouraring.com (verified 2026-06-15). Xiaomi Smart Band 9: mi.com (verified 2026-07-08).
What's the difference between the Oura Ring 4 and Xiaomi Smart Band 9?
Where the two actually differ on the specs we track (4 of 8). Matching specs are omitted.
- Form factor: Oura Ring 4 ring vs Xiaomi Smart Band 9 band
- Battery days: Oura Ring 4 8 vs Xiaomi Smart Band 9 21
- Subscription required: Oura Ring 4 true vs Xiaomi Smart Band 9 false
- Water resistance (m): Oura Ring 4 100 vs Xiaomi Smart Band 9 50
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Oura Ring 4
Two whitelisted hands-on testers (TechRadar, Engadget) call the Oura Ring 4 the best smart ring, praising comfort, sleep tracking and the redesigned app. Both flag the mandatory $5.99/month subscription that paywalls essential features. In real-world use, TechRadar drained a Size 10 ring in about five and a half days of constant use with workouts, while Engadget regularly got seven days on the same size over two months of lighter use. (Numeric measured values were dropped because the digit forms did not literally appear in the source text; the battery claims survive within verbatim quotes.) (2 sourced reviews, 2 lab-tested.)
Praised: Best-in-class smart ring; comfortable, elegant titanium design; Highly accurate sleep tracking (near-polysomnography); Multi-day battery life in real use (roughly 5.5-7 days on a Size 10).
Flagged: Mandatory $5.99/month subscription paywalls essential features and hurts value; Automatic activity/workout detection is unreliable (false positives).
Xiaomi Smart Band 9
No sourced tester review yet.