Your phone contains two closely related but distinct motion sensors: an accelerometer and a gyroscope. When either one fails — after a drop, a repair, or a software glitch — you might notice your screen refusing to rotate, AR apps drifting off course, or games no longer responding to tilt. Here is how to test both sensors in under a minute using nothing but your browser.
Accelerometer vs Gyroscope: What's the Difference?
Both sensors measure movement, but they track different things. Understanding which one does what makes it easier to diagnose problems.
| Sensor | What It Measures | Powers |
|---|---|---|
| Accelerometer | Linear force (gravity + movement) along X, Y, Z axes | Screen auto-rotate, step counter, tilt controls |
| Gyroscope | Rate of rotation around each axis | AR apps, image stabilization, VR mode, shooter games |
A phone with a working accelerometer but a broken gyroscope will still auto-rotate correctly, but AR and stabilization features will fail. A broken accelerometer affects auto-rotate and any tilt-based feature.
How to Test Your Phone's Motion Sensors Online
The quickest way is to use the free Motion Sensor Test — it reads live accelerometer and gyroscope data directly from your browser, with no app installation required.
- Open the test on your phone — the tool must run on the device you want to test, not on a desktop browser.
- Tap "Start Sensor Scan" — on iPhone, a permission prompt will appear; tap Allow.
- Move the phone slowly — tilt it forward, backward, left, and right. Watch the Alpha, Beta, and Gamma values update.
- Check the acceleration readings — the Accel X, Y, Z values should change as you move the phone.
All six values update smoothly? Both sensors are working. Some values frozen at 0 or unchanged? That axis or sensor may be damaged or blocked by permissions.
📱 Test your sensors now: Open the MyDeviceScan Motion Sensor Test on your phone for live accelerometer and gyroscope readings — no install needed.
Why Won't My Screen Auto-Rotate?
If your screen no longer rotates when you turn the phone sideways, start with the simplest check: the rotation lock toggle. Swipe down your notification shade — look for a "Portrait Lock," "Auto Rotate," or padlock icon. If that's not the culprit, the issue is likely the accelerometer.
Steps to diagnose auto-rotate failure:
- Open the Motion Sensor Test and tap Start.
- Hold the phone upright, then slowly rotate it to landscape. Watch the Beta and Gamma values.
- If Beta and Gamma do not change as you tilt, the accelerometer is not reporting data — the sensor or its connector needs inspection.
- If values do change but the screen still will not rotate, the problem is in the OS settings or a specific app overriding rotation — check Settings → Display → Auto-rotate.
How to Check the Gyroscope After a Drop
Drops are the leading cause of gyroscope failure. The sensor is small and mounted on the main logic board; a hard impact can crack the sensor or loosen its solder connections. Testing it immediately after a drop can tell you whether service is needed before you rely on the phone for photography or navigation.
- Open the Motion Sensor Test and start the scan.
- Hold the phone flat (face up) and slowly spin it clockwise on a table. Watch the Alpha value — it should increase from 0 to 360 as you rotate.
- Tilt forward and back. Beta should change from roughly 0 to 90.
- Tilt left and right. Gamma should shift between −90 and 90.
If any of these axes shows zero movement or erratic jumps, the gyroscope hardware was likely damaged. A repair shop can confirm with a diagnostic and check whether the sensor connector is loose — a common and often inexpensive fix.
What Apps and Games Need the Gyroscope?
Many popular features depend on gyroscope data that goes beyond simple tilt:
- AR apps (Pokémon GO, IKEA Place, Google Maps AR navigation) — use the gyroscope to keep virtual objects anchored as you move the camera.
- FPS and racing games — use gyroscope for aim assist and steering so the view tracks your physical wrist rotation.
- Video recording stabilization — the phone's electronic image stabilization samples the gyroscope hundreds of times per second to counteract hand shake.
- Panorama photography — the camera uses gyroscope data to stitch frames together seamlessly.
- VR headset modes — head tracking in Google Cardboard and similar apps is gyroscope-only.
If you notice any of these features misbehaving — AR drift, shaky video despite stabilization being on, or panoramas that stitch incorrectly — run the motion sensor test to see if the gyroscope axis involved is working.
Frequently Asked Questions
How do I test my phone's gyroscope online?
Open the MyDeviceScan Motion Sensor Test on your phone's browser, tap Start Sensor Scan, and grant motion permission if prompted. Then slowly rotate your phone in all directions. If the alpha, beta, and gamma values update smoothly, your gyroscope is working. Frozen values or no data at all usually point to a hardware fault or a blocked sensor permission.
What is the difference between an accelerometer and a gyroscope?
The accelerometer measures linear acceleration — forces along the X, Y, and Z axes — including the constant pull of gravity. This is what tells your phone which way is down and powers the auto-rotate feature. The gyroscope measures the rate of rotation around each axis. Together they give the phone full 3D motion awareness needed for AR apps, gaming, and image stabilization.
Why won't my phone screen auto-rotate?
Auto-rotate requires a working accelerometer. First check that you have not locked screen rotation: swipe down the notification shade and look for a rotation lock or portrait lock toggle. If the toggle is off but rotation still does not work, open a motion sensor test and see if the accelerometer values change when you tilt the phone. No change means the accelerometer may need service.
How do I check my gyroscope after dropping my phone?
Open the Motion Sensor Test immediately after a drop and tap Start Sensor Scan. Slowly rotate the phone through all angles — tilting forward and back, side to side, and spinning flat. Watch the alpha, beta, and gamma values. If any axis shows no movement, jumps erratically, or stays at zero, the gyroscope sensor (or its connector inside the phone) may have been damaged and the device should be inspected by a repair technician.
What does it mean when accelerometer values are frozen?
Frozen accelerometer readings — values that do not change no matter how you move the phone — typically indicate a failed sensor, a disconnected ribbon cable (common after drops), or a locked permission. On Android, check Settings → Apps → your browser → Permissions → Motion or Physical Activity. On iPhone, go to Settings → Privacy & Security → Motion & Fitness. If permissions are fine and values still do not move, the hardware sensor likely needs replacement.
Which apps and features use the gyroscope?
The gyroscope powers features that need precise rotation tracking: AR apps (like Google Lens and games using ARKit or ARCore), first-person shooter games with aim assist, video stabilization during recording, VR headset modes, and panorama photography stitching. If your gyroscope is broken, AR features will drift or fail, and some games will feel unresponsive to tilting.