Between the Ring 4 and Smart Band 9, the Ring 4 comes out ahead in water resistance, while the Smart Band 9 wins on battery life and sport modes. Overall, the Ring 4 scores 52.9 and the Smart Band 9 scores 78.8 on our Mars Score.
Which should you buy?
The Smart Band 9 is the clear pick on raw spec strength, leading by 25.9 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the Ring 4 if you care most about water resistance. The biggest gaps in its favor are water resistance.
Pick the Smart Band 9 if you care most about battery life and sport modes. Its strongest claims are battery life, sport modes.
Both ship with comparable gps, spo2, so those specs don't separate the two — focus on the differences below.
Bottom line: the Smart Band 9 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Oura - Ring 4 wins
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
Why Xiaomi - Smart Band 9 wins
- ▲Battery life — 162.50% more. 21 days vs 8 days.
- ▲Sport modes — 110.00 more. 150 vs 40.
Spec comparison
Fitness
| Spec | Oura - Ring 4 | Xiaomi - Smart Band 9 |
|---|---|---|
| GPS | false | false |
| Heart rate | true | true |
| SpO2 | true | true |
| Sleep tracking | true | true |
| Sport modes | 40 | 150lead |
Battery
| Spec | Oura - Ring 4 | Xiaomi - Smart Band 9 |
|---|---|---|
| Battery life | 8 days | 21 dayslead |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Design
| Spec | Oura - Ring 4 | Xiaomi - Smart Band 9 |
|---|---|---|
| Display size | 0 " | 1.62 "lead |
| Weight | 3.3 glead | 16 g |
Frequently asked
Spec-level deep dives
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