August 16, 2026 · 12 trackers tested
Gold Tested
Sleep trackers range from wrist-worn fitness bands to under-mattress pads. We compared 12 trackers against polysomnography (clinical sleep lab) data and found accuracy varies wildly — some miss REM sleep entirely.
Oura Ring Gen 4 by Oura
The Oura Ring Gen 4 matched polysomnography data within 8% for sleep staging, compared to 15-40% for wrist-worn competitors. Its HRV readings correlated at r=0.94 with clinical measurements. The ring
Six panelists wore all devices simultaneously for 14 nights, with two nights in a certified sleep lab for polysomnography comparison. We measured sleep stage detection accuracy, total sleep time error, and heart rate variability correlation.
The Oura Ring Gen 4 matched polysomnography data within 8% for sleep staging, compared to 15-40% for wrist-worn competitors. Its HRV readings correlated at r=0.94 with clinical measurements. The ring form factor also means you actually wear it every night.
Specifications
| Form factor | Ring |
| Sensors | PPG, temperature, accelerometer |
| Battery | 5-7 days |
| Water resistant | 100m |
| Connectivity | Bluetooth 5.3 |
| Subscription | $5.99/mo for advanced features |
The Oura Ring Gen 4 earns our top pick because it outperformed the competition in the metrics that matter most. At an overall score of 9.2 against a category average of 6.4, the gap speaks for itself. If you are looking for the best in this category, start here.
Oura