Gyroscope and accelerometer test

The accelerometer measures acceleration including gravity, which reveals tilt and shake. The gyroscope measures how fast the device rotates.

Desktops usually have no motion sensors. On iPhone you must allow Motion & Orientation access. Also confirm the page is HTTPS.

The magnetometer needs calibration. Move your phone in a figure eight and keep it away from magnets or metal.

Open this page on your phone or tablet, press Start sensors and allow motion access if asked. Tilt, rotate and shake the device. The live orientation, acceleration and rotation values should follow your movement. If a value stays at zero, that sensor may be missing or blocked.

Not reliably. Browsers have removed access to the proximity sensor, so a web page cannot read it. This test covers the gyroscope, accelerometer and compass instead. To check your proximity sensor, make a phone call and cover the top of the screen with your hand: the screen should switch off. Many phones also have a hidden diagnostics menu for this.

Five common sensors are: the accelerometer, which measures acceleration and tilt; the gyroscope, which measures rotation; the magnetometer (compass), which senses magnetic fields; the proximity sensor, which detects nearby objects; and the ambient light sensor, which measures brightness. Other examples include temperature, pressure and humidity sensors.

A sensor detects a physical change and turns it into a signal that a device can read. Depending on the type, it can detect motion, rotation, orientation, light, sound, temperature, pressure, humidity, magnetic fields, distance or the presence of an object. Phones use these to rotate the screen, count steps, dim the display and show your direction.