Why do I see about 9.8 m/s² when the phone is still?
Those are gravity-inclusive readings. A stationary phone can show roughly 9.8 m/s² of total acceleration even though its linear acceleration is near zero.
PHONE / MOTION
Accelerometer Test.
Hold the phone firmly and move it gently in each direction. Avoid dropping or shaking it hard.
Linear acceleration0.00m/s²
X axis0.00
Y axis0.00
Z axis0.00
Peak 0.00Sample rate 0 Hz
Move your phone to inspect live acceleration on the X, Y, and Z axes. The display distinguishes motion from gravity when the browser supplies both.
02 / METHOD
How to read the accelerometer
Linear acceleration is movement with gravity removed, measured in metres per second squared. When the phone is still, its linear readings should settle near zero; gravity-inclusive readings usually show a force near 9.8 m/s² across the three axes.
03 / LIMITS
Why readings may differ
Some browsers provide only acceleration including gravity. The page labels that fallback instead of treating it as linear motion. HTTPS, sensor access, calibration, and the phone’s orientation also affect what you see.
Accelerometer test questions
Why is there no acceleration data?
Motion permission, browser support, or device hardware may prevent readings. Open the page over HTTPS, allow access, and try moving the phone gently.