Place your finger on the camera lens. Breathe with the pacer. Watch your coherence score rise in real time. No wearables, no app downloads — just your browser and five minutes.
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How It Works
Cover the rear camera with your fingertip. The camera flash illuminates your skin and detects blood flow changes — the same principle as a pulse oximeter.
Follow the breathing circle at 6 breaths per minute — the resonance frequency where your heart and breathing synchronize for maximum HRV.
Watch your coherence score rise in real time. After 5 minutes, get a full summary with your heart rate, HRV metrics, and coherence ratio.
The Science
At ~6 breaths per minute, your heart rate naturally oscillates in a smooth, coherent wave. This is called cardiac coherence — a state where your autonomic nervous system shifts toward balance between fight-or-flight and rest-and-digest.
Research shows regular coherence training reduces stress, improves focus, and builds emotional resilience. HRV Coach measures this in real time using photoplethysmography (PPG) — the same technology in hospital pulse oximeters.
No account needed. Takes 5 minutes. Works right now.
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