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GEARCHECK LAB
Mobile Sensor Lab // Linear Motion

PHONE ACCELEROMETER TEST

Move, tilt and rest a sensor-equipped phone or tablet to inspect the acceleration values your browser exposes. GearCheck Lab shows X/Y/Z acceleration including gravity, vector magnitude, browser event cadence and a repeatable still-device stability check without uploading motion readings.

LOCAL SENSOR DATAReadings stay inside this browser session.
Permission-aware diagnostic

Acceleration response & gravity vector

SENSORS OFF
LIVE gravity-vector magnitude historyStationary total is typically near 9.8 m/s²

How to test an accelerometer

  1. Open this page on the phone or tablet you want to test.
  2. Press Start Accelerometer and grant motion permission if asked.
  3. Place the device flat and still; confirm live values and event count change from their placeholders.
  4. Slowly tilt the device so gravity moves between the X, Y and Z axes.
  5. Gently move it forward/back, left/right and up/down while watching the linear-acceleration and magnitude readings respond.
  6. Place it flat and still again and run the 5-second stability check.

What the gravity vector should look like

Where available, accelerationIncludingGravity includes Earth’s gravity. A stationary device usually reports a total vector magnitude around 9.8 m/s², distributed across X, Y and Z according to orientation.

Do not use one exact axis value as a pass/fail target. Coordinate direction changes with device orientation and browser implementation. Look for responsive axes and a plausible total vector.

Linear acceleration vs acceleration including gravity

Some browsers also expose acceleration, which attempts to remove gravity. GearCheck Lab shows its magnitude separately when available. If the browser leaves those values null, the page does not invent them; the gravity-inclusive values can still be useful.

What the stability check measures

The five-second check samples the gravity-vector magnitude while the device is resting. It reports the average, variation and largest deviation seen during that browser session.

It is a repeatability check, not factory calibration. Table vibration, hand movement, browser filtering and sensor noise all influence the result.

Why values may stay blank

  • The desktop or laptop may not have a browser-exposed accelerometer.
  • Motion permission may be denied or not requested from a user gesture.
  • The browser may restrict motion sensors for privacy/security.
  • The device may expose orientation but not DeviceMotion acceleration fields.
  • A system-level privacy setting can block sensor access.

What counts as useful evidence?

Strong evidence is repeatable: one or more axes remain frozen while you deliberately move through all directions, data repeatedly stops after permission succeeds, or the behavior differs sharply between the same phone in two current browsers.

One odd number is weak evidence. Consumer accelerometers have bias and noise, and browsers can filter or quantize data.

Accelerometer test FAQ

Does 9.8 m/s² mean my accelerometer is perfect?

No. A total near Earth gravity is a useful sanity check when the device is stationary, not a calibration certificate.

Why is one axis near ±9.8 while the others are near zero?

Gravity projects onto the axes according to how the device is oriented. Rotate the device and the dominant axis should change.

Why is linear acceleration unavailable?

Some browsers expose only acceleration including gravity. GearCheck Lab reports availability honestly rather than deriving a fake “raw” value.

Are readings sent anywhere?

No. The event values are processed locally to update the display and short in-memory chart.