Short answer: neither Android nor iOS lists your sensors anywhere in Settings. A device info app enumerates them directly from the system, and that is the only reliable way to know what you actually have.
The full sensor inventory
Modern phones contain somewhere between eight and fifteen sensors. Here is what each is for and how universal it is.
Motion and position
| Sensor | What it does | How common |
|---|---|---|
| Accelerometer | Measures linear acceleration and gravity direction — screen rotation, step counting, shake gestures | Universal |
| Gyroscope | Measures rotation rate on three axes — VR, image stabilisation, precise orientation | Most mid-range and above |
| Magnetometer | Measures magnetic field — compass, metal detection | Almost universal |
These three combined give "9-axis" sensor fusion, which is what produces stable orientation tracking.
Environment
| Sensor | What it does | How common |
|---|---|---|
| Ambient light | Automatic screen brightness | Universal |
| Proximity | Blanks the screen during calls | Universal |
| Barometer | Air pressure — altitude, floor detection, faster GPS lock | Flagships mostly |
| Thermometer | Internal component temperature, not room temperature | Universal (internal only) |
| Hall effect | Detects magnets — smart case covers | Common |
Biometric and other
| Sensor | What it does |
|---|---|
| Fingerprint | Optical, ultrasonic or capacitive |
| Face / depth | Structured light or IR dot projector on Face ID devices |
| Heart rate | Rare on phones now; mostly moved to watches |
| LiDAR / ToF | Depth measurement for AR and camera focus, on some Pro models |
Not really sensors
A few things marketed as sensors are computed values, not hardware:
- Step counter — derived from the accelerometer
- Significant motion — derived
- Rotation vector / game rotation vector — fused from accelerometer, gyroscope and magnetometer
- Gravity / linear acceleration — the accelerometer signal split into two components
A sensor list showing thirty entries usually includes a dozen of these "virtual" sensors.
Checking what you have
A device info app is the practical answer. A device info app lists every sensor the system reports, with vendor, maximum range, resolution and power draw, and usually shows live values so you can confirm each one responds.
On Android, some manufacturers include a hidden hardware test menu reached through a dialler code. These vary by brand and are undocumented. They are read-only diagnostics, but be careful not to wander into engineering menus that change radio settings.
On iPhone, there is no built-in sensor list at all. An app is the only route.
Testing individual sensors
You can check several without installing anything:
- Magnetometer — our compass tool. If it reads a stable heading that changes as you turn, the sensor works.
- Accelerometer — rotate the phone. If auto-rotate works, the accelerometer works.
- Microphone — our microphone test.
- Touchscreen digitiser — our screen test traces your finger and reveals dead zones.
- Proximity — make a call and cover the top of the screen with your hand. The display should blank.
- Ambient light — enable auto-brightness and cover the top of the screen. Brightness should drop within a second or two.
- GPS — our GPS accuracy tool.
Common sensor faults and what they look like
Screen does not blank during calls. Proximity sensor blocked. Ninety percent of the time it is a screen protector without the correct cutout, or dirt in the earpiece slot. Clean it and check the protector before anything else.
Auto-rotate stopped working. Either auto-rotate is switched off in quick settings, or the accelerometer has failed. Check the toggle first — this is the most common false alarm.
Compass points the wrong way. Magnetic interference, not usually a fault. See how to calibrate your phone compass.
Auto-brightness behaves erratically. Often the ambient light sensor is partly covered by a case or protector. It sits in the same cutout region as the proximity sensor.
Games with tilt controls do not work. Missing gyroscope. Check the sensor list — some budget phones genuinely do not have one, and no software fix exists.
Why sensors matter when buying
If you care about any of these, check for the sensor before buying:
- VR or 360° video → needs a gyroscope
- Hiking with altitude tracking → needs a barometer
- Navigation and orienteering → needs a magnetometer
- AR measurement apps → benefits substantially from LiDAR/ToF
- Smart case covers that wake the screen → needs a hall effect sensor
Spec sheets routinely omit the sensor list, and review sites often do not test it. A device info app run in a shop takes thirty seconds and answers it definitively.
