Free tool
Camera HRV test
Cover your phone's rear camera with a fingertip for a minute. The test tracks your pulse in the camera image and estimates your HRV from it.
What this test measures
Each heartbeat pushes blood into your fingertip, which changes how much light passes through it. The camera sees this as a pulse. The time between pulses gives pulse rate variability (PRV), a close relative of HRV.
It is an estimate. Pulses in a fingertip are less sharp than heartbeats in an ECG, so a camera reading is less accurate than a chest strap, especially when you move. For the most reliable numbers, use the Chest-strap HRV test.
Your browser asks for camera access. The picture is never shown to anyone or stored: each frame is reduced to its average colour on this device.
How to take a good reading
- Use your phone, not a laptop: the test needs the rear camera and its torch.
- Sit down and rest your hand and phone on a table. Warm your hands first if they are cold.
- Cover the rear camera lens and the torch completely with the pad of one fingertip. Press lightly; the preview should glow red.
- Keep still, breathe normally and do not talk until the recording ends.
- Measure at the same time each day, ideally soon after waking, so readings are comparable.
If the pulse signal is too weak or noisy, the test shows no result and tells you how to try again, rather than giving you a number it cannot stand behind.
Read more
Everything is processed on your device. Camera frames are reduced to an average colour on your phone and never stored or sent. If you are signed in, you can choose to save the result to your readings; only then are the RMSSD, mean heart rate and time sent. Privacy