A magnetometer is a sensor that measures magnetic fields, including Earth's magnetic field. Your smartphone uses it to detect magnetic north, enabling digital compass apps like this one. It works by sensing the strength and direction of the magnetic field, which varies slightly depending on your location and nearby metal objects.

Accuracy depends on your device's sensors and calibration. With proper calibration (moving your phone in a figure-8 pattern), most modern devices can achieve an accuracy within 5 degrees. Keep your device away from strong magnetic fields, metal cases, or electronic interference for the best results.

Calibration helps the magnetometer filter out magnetic interference from the device itself and its surroundings. If the heading seems wrong or drifts, perform the figure-8 motion shown on most phones to recalibrate. This tool will display a “needs calibration” hint when the sensor reports low accuracy.

Most modern smartphones and tablets include a magnetometer. If you see the compass moving after you enable it, your device supports it. If nothing happens, your browser may not support orientation sensors, or you may need to grant permission (especially on iOS 13+). Desktop browsers usually do not have a magnetometer.

On iOS 13 and later, you must explicitly grant permission for device orientation and motion sensors. Tap the “Enable Compass” button above, and your browser will ask for permission. If you previously denied it, reset the permission in Settings > Safari > Motion & Orientation Access.

Laptops and desktop computers rarely include a magnetometer. This tool is designed for mobile devices (smartphones/tablets) that have the necessary sensors. Open this page on your mobile browser for the full experience.