Accelerometer Test
Move or shake your device to check that the motion sensor responds.
Peak force
0.00 m/s²
Shakes
0
Sensor
—
Your test runs locally in your browser. No device data is uploaded.
How to use the accelerometer test
Press start and allow motion access when the browser asks. Rest the device flat first, then tilt it through each axis and give it a firm shake. The bars should move as you tilt, and the shake counter should tick up.
What this test checks
The test reads the browser's device motion events, reporting acceleration along three axes in metres per second squared, gravity included. X runs across the screen, Y up and down it, Z through it — which is why a device lying flat reads close to 9.8 on Z and near zero elsewhere.
That resting reading is the most useful single result. A steady value near 9.8 on one axis proves the sensor is alive without moving anything, and peak force plus the shake counter confirm it responds across its range rather than reporting a fixed number.
Common motion sensor problems
Readings stuck at zero almost always mean permission was declined, the page is not on HTTPS, or the device has no accelerometer — desktops generally do not. Values that jump wildly while the device is still, or that never settle to a sensible resting reading, suggest a failing sensor, which on a phone usually means a board-level repair.
Frequently asked questions
- What do the X, Y and Z values mean?
- Acceleration along each axis in metres per second squared, including gravity. X runs across the screen, Y up and down it, Z through it. That is why a phone lying flat on a table reads close to 9.8 on Z and near zero on the other two — gravity alone.
- Why is a value around 9.8 shown when my phone is completely still?
- Because gravity is a constant acceleration and the sensor cannot tell it apart from any other. A reading near 9.8 on one axis at rest is the clearest sign the sensor is working correctly, not a fault.
- The readings stay at zero. What should I check?
- Permission first: iOS requires explicit motion access each session and blocks it entirely if Motion & Orientation Access is off in Safari settings. Then check the page is on HTTPS. If both are fine on a device that has the sensor, the sensor or its connection is at fault.
- What is the shake counter for?
- It counts movements past roughly two and a half times gravity, which is a deliberate shake rather than ordinary handling. It is a quick way to confirm the sensor responds across its range instead of only reporting a resting value.
- Is this the same as the gyroscope?
- No, and phones have both. The accelerometer measures straight-line force, which is what step counters and shake gestures use. The gyroscope measures rotation, which is what screen rotation and motion controls use. Test them separately.