Oura and Ultrahuman are the two leading smart ring brands for health tracking. The Oura Ring Gen 4 builds on years of sleep science leadership, while the Ultrahuman Ring AIR offers a subscription-free alternative with metabolic health integration. Both provide HRV, sleep, and readiness tracking in a comfortable ring form factor.
Comparison Overview
| Category | Oura Ring 4 | Ultrahuman Ring Air |
|---|---|---|
| HRV Accuracy | Multi-sensor PPG, temperature, SpO2; well-validated ✓ | PPG optical sensor with skin temperature |
| Oura has more published validation and a longer track record | ||
| Sleep Tracking | Detailed sleep stages, Sleep Score, optimal bedtime ✓ | Sleep stages, sleep index, movement analysis |
| Oura's sleep algorithm is more mature and detailed | ||
| Battery Life | Up to 8 days ✓ | Up to 6 days |
| Oura Gen 4 offers slightly better battery endurance | ||
| Subscription | $6/month required for full features | No subscription — all features included ✓ |
| Ultrahuman's no-subscription model is a major cost advantage | ||
| Comfort/Design | Titanium, multiple finishes, slightly thicker | Titanium, lightweight (< 6g), slim profile ✓ |
| Ultrahuman Ring AIR is noticeably lighter and thinner | ||
| Health Features | Readiness, resilience, cycle tracking, SpO2, stress ✓ | Movement index, metabolic score (with CGM), skin temperature |
| Oura offers a broader suite of health metrics | ||
| App Quality | Polished app, Tags, Trends, guided content ✓ | Clean app, PowerPlugs, metabolic health focus |
| Oura's app is more feature-rich with better long-term trend views | ||
The Bottom Line
Choose the Oura Ring Gen 4 if you want the most complete smart ring experience with superior sleep tracking, a mature HRV algorithm, and the broadest health feature set. Choose the Ultrahuman Ring AIR if you want a lighter ring with no subscription fees and are interested in metabolic health integration via Ultrahuman's CGM platform. Both are excellent rings, but Oura remains the overall leader for HRV and sleep.
Detailed Reviews
Oura Ring 4
Best for those who prioritize comfort and discretion. The ring form factor is ideal for sleep tracking, though the...
Full reviewUltrahuman Ring Air
A solid Oura alternative with no subscription fees. Strong HRV and sleep tracking in a comfortable form factor. Best...
Full review