Versus Engine
Circular Ring 2 vs Whoop 4.0
Specs, price and the one trade-off that actually decides it — Circular Ring 2 against Whoop 4.0, side by side.
Cheaper to start
Whoop 4.0
Starts about $60 lower.
Rated higher
Whoop 4.0
9.2 vs 8.8 on our design scale.
Standout
Circular Ring 2
Native ECG sensor for AFib detection
Circular Ring 2
A smart ring with native ECG and no subscription, aimed at the European market.
Where it wins, where it doesn't
Pros
- Native ECG sensor for AFib detection
- No subscription — a saving that compounds over years
- Haptic notifications on the ring itself
Cons
- Finish and industrial design trail the Oura Ring 4
- Data interpretation less mature than Oura's
- Global support network still being established
Specifications
- SensorsECG, PPG, temperature, 3-axis accelerometer
- Battery8 days power mode, 5 days performance
- battery_life—
- Charging30 minutes, wireless case
- ComplianceGDPR and HIPAA
- MaterialTitanium, hypoallergenic interior
- Size2.55 mm thick, 7.8 mm wide, 3 g
- SizesUS 6-14
- subscription—
- Thickness2.55 mm
- tier—
- Water ratingIP68
- Weight3 g
Whoop 4.0
A screenless fitness and recovery tracker focused on physiological data.
Where it wins, where it doesn't
Pros
- Exceptional recovery analytics
- Screenless design removes distractions
- Comfortable for 24/7 wear
Cons
- Requires a monthly subscription
- No screen for quick time checks
Specifications
- SensorsHR, HRV, Temp, SpO2
- Battery—
- battery_lifeUp to 5 days
- Charging—
- Compliance—
- Material—
- Size—
- Sizes—
- subscriptionRequired
- Thickness—
- tierpremium
- Water rating—
- Weight—