How it works

The science in plain language.

Pulsira uses a well-studied optical technique called photoplethysmography, or PPG. Here’s what happens during a reading.

Light meets skin. Room light or your screen’s glow falls on your face.
Blood volume pulses. With every heartbeat, a little more blood flows through tiny vessels near the surface, and the skin absorbs slightly more light.
The camera notices. Those changes are far too small to see, but averaged across many pixels they form a clear wave.
Pulsira checks quality. Brightness, motion and timing are checked continuously. No estimate is shown until the signal is good enough.
You get a reading. The rhythm of the wave becomes an experimental beats-per-minute estimate, shown next to its signal quality.

For a better reading

Four things that matter.

Soft, steady light works best. Avoid strong backlight or flicker.

Rest your hand or sit back. Motion is the biggest source of noise.

Keep your face inside the on-screen outline, at a comfortable distance.

Give it a little time. Longer, steadier readings settle more.