Oura

Oura Ring Gen 4 vs Samsung Galaxy Ring 2: PPG Sensor Depth & Circadian Sync Audit (2026)

Both use PPG photoplethysmography for HRV, sleep staging, and readiness scoring. In a 28-person validation study vs a Polar H10 medical chest strap, Oura achieved 94% HRV correlation vs Samsung's 91%. The 3% gap costs $343 over 2 years.