The Accuracy Database
The complete ledger of consumer sleep trackers, tested against clinical EEG baselines for a minimum of 14 nights. Sorted by overall Pearson correlation.
| Device / Model | Form Factor | TST Total Sleep Time | REM Rapid Eye Movement | N3 Deep Slow Wave Sleep | Wake Wake After Onset | Details |
|---|---|---|---|---|---|---|
| Apple Watch Ultra 2 | Wrist | 0.94 | 0.81 | 0.62 | 0.78 | Lab Notes |
| Oura Ring Gen 3 | Ring | 0.91 | 0.74 | 0.76 | 0.82 | Lab Notes |
| Whoop 4.0 | Wrist/Bicep | 0.89 | 0.72 | 0.58 | 0.70 | Lab Notes |
| Fitbit Charge 6 | Wrist | 0.88 | 0.76 | 0.65 | 0.68 | Pending |
| Withings Sleep Mat | Mattress Mat | 0.76 | 0.41 | 0.45 | 0.52 | Lab Notes |
| Google Nest Hub (Gen 2) | Radar (Bedside) | 0.62 | 0.31 | 0.34 | 0.44 | Pending |
Data Legend: Values represent Pearson correlation coefficients (r) against clinical PSG baseline over a minimum 14-night period.
Green (>0.9) indicates exceptional agreement. Red (<0.65) indicates poor agreement, suggesting the device's algorithm is guessing based on demographic averages rather than actual physiological measurement.