How does it measure heart rate using a camera?

It uses a technique called photoplethysmography (PPG). The flash illuminates your fingertip, and the camera picks up the tiny changes in how much red light is absorbed as blood pulses through your capillaries. Those pulses are counted to calculate BPM.

Is it medically accurate?

Results are typically within a few BPM of a standard pulse oximeter for resting measurements, but this tool is not a medical device. Do not use it for clinical decisions or to monitor a medical condition.

Why is my reading jumping around or showing an error?

Finger movement is the most common cause. Rest your elbow on a surface, cover the lens fully, keep completely still, and avoid pressing so hard that you cut off blood flow.

Does it store or upload any camera footage?

No. Video frames are processed in real time on your device to extract the pulse signal only. No images or data are stored or transmitted.

Heart Rate

APP

Measure your pulse through the camera and flash.

Best on the app

Heart Rate needs your phone's hardware

It reads your pulse through the camera + flash. Download Carbide free to use it — plus all 111 tools, fully offline.

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What it does

Heart Rate lets you measure your pulse without any wearable or external hardware — just your phone's rear camera and flash. Place your fingertip over the lens and flash, and the tool detects the subtle color changes in your skin caused by blood flowing through your capillaries with each heartbeat, then displays your beats per minute in real time. It's a quick way to check your resting heart rate after waking, monitor recovery after light exercise, or simply satisfy curiosity. The tool is completely free, requires no account, and works fully offline — your camera frames are processed on-device and never stored or transmitted. Get a reading in about 30 seconds.

How to use the Heart Rate

Open Heart Rate and place your index fingertip gently over the rear camera lens and flash — don't press too hard.
Keep your finger still and hold steady; the flash will stay on to illuminate your fingertip.
Watch the on-screen waveform as the tool detects your pulse from blood flow changes.
After about 15–30 seconds, your BPM reading will appear on screen.
Remove your finger to stop and tap again to take another reading.

Frequently asked questions

How does it measure heart rate using a camera?: It uses a technique called photoplethysmography (PPG). The flash illuminates your fingertip, and the camera picks up the tiny changes in how much red light is absorbed as blood pulses through your capillaries. Those pulses are counted to calculate BPM.
Is it medically accurate?: Results are typically within a few BPM of a standard pulse oximeter for resting measurements, but this tool is not a medical device. Do not use it for clinical decisions or to monitor a medical condition.
Why is my reading jumping around or showing an error?: Finger movement is the most common cause. Rest your elbow on a surface, cover the lens fully, keep completely still, and avoid pressing so hard that you cut off blood flow.
Does it store or upload any camera footage?: No. Video frames are processed in real time on your device to extract the pulse signal only. No images or data are stored or transmitted.

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