No wearable, no extra hardware. Remote photoplethysmography (rPPG) turns tiny, invisible-to-the-eye color changes in your skin into a heart rate reading - the same physical principle a pulse oximeter uses, picked up here by an ordinary camera instead of a dedicated sensor.
The camera never leaves your device - a clip is analyzed and, unless you're signed in, thrown away immediately after. Everything below is real: the same pipeline that produces your reading also produces the numbers underneath it.
An OpenCV detector finds your face every frame and tracks a forehead region - the most motion-stable, least occluded patch of skin.
Every heartbeat shifts how much green light your skin reflects, by an amount too small to see. Averaging that region per frame builds a signal a Butterworth filter and FFT can turn into a heart rate.
The region below your face is watched with optical flow instead of color - the small rise and fall of your chest and shoulders, band-passed to the breathing range, running the same instant the color signal does.
A reading reports how concentrated its signal's energy actually was, plus a separate check for values outside a plausible resting range - so a confidently wrong number doesn't ship silently.
Flip on Dev Mode before recording and a live overlay draws the same three regions the pipeline actually measures, updated live - not a mockup, the real detector output. Here's what those boxes mean:
Processed on this device only - nothing is saved unless you sign in.
Sit still, face the camera, good even lighting works best. No account needed to try it.
Records a short check-in clip every few minutes while this tab stays open (it can sit in the background or another window - it doesn't need to be the active tab) and sends a browser notification if a reading comes back unusually low. This needs the browser to keep running; it can't check anything while the tab is closed or the computer is asleep.
No sessions yet - record a clip above to start your history.
| When | HR | BR | Confidence (HR / BR) |
|---|
Vitals Tracker is a personal wellness demo, not a product - see how it works above for the actual mechanism (rPPG, the same principle a clip-on pulse oximeter uses). What's worth being upfront about is what it doesn't do.
It is not a medical device. Lighting, movement, and skin tone all affect accuracy, and that's inherent to the technique, not a bug being hidden - which is why every reading ships with a confidence score and a plausibility check instead of a bare number. Treat it as a genuinely interesting piece of applied signal processing, not a diagnostic tool, and don't make health decisions from it.
The whole pipeline - face detection, band-pass filtering, FFT peak-picking, optical flow - runs locally on the server that serves this page; a recorded clip is processed and, unless you're signed in and choose to keep it, discarded.