Smart rings and screenless fitness bands have become the two most popular ways to track sleep without a bright watch face on your wrist. The Nimbus Ring 2 and the Tempo Band are leaders in each category. We wore one on each hand for a month.
At a glance
Our pick
Nimbus Ring 2
8.6/10
Best for discreet, all-day wear and sleep tracking
Tempo Band
8.1/10
Best for training data and value
The Nimbus Ring 2 is the better sleep tracker and the one you will forget you are wearing. The Tempo Band makes more sense if workouts matter as much as sleep.
| Spec | Nimbus Ring 2 Winner | Tempo Band |
|---|---|---|
| Price | $299 | $199 |
| Subscription | None | $6 per month |
| Battery (tested) | 6 days | 5 days |
| Weight | 4 g | 27 g |
| Workout tracking | Basic | Detailed, with strain score |
| Water resistance | 100 m | 50 m |
| Our score | 8.6 | 8.1 |
Round 1: Comfort
At 4 grams, the Nimbus Ring 2 disappears on your finger. The Tempo Band is comfortable, but you always know it is there, especially when typing.
Round winner: Nimbus Ring 2
Round 2: Sleep tracking
Both detect sleep and wake times accurately. The Nimbus provides clearer sleep-stage estimates and a more useful morning summary.
Round winner: Nimbus Ring 2
Round 3: Fitness tracking
The Tempo Band is built for athletes, with continuous heart rate during workouts and a clear strain score. The ring’s workout tracking is basic by comparison.
Round winner: Tempo Band
Round 4: Cost over time
The Tempo Band is cheaper upfront but requires a subscription. After a little over a year and a half, total costs are about even.
Round winner: Tie
Final verdict
Nimbus Ring 2 for sleep
If better sleep is your main goal, the Nimbus Ring 2 is the clear choice. If you train seriously, the Tempo Band offers more useful data.
