Sensor Test
Check your device's accelerometer, gyroscope, orientation and motion sensors live, right in your browser. Works best on phones and tablets.
Sensor test
Tap “Run test” to start reading your accelerometer, gyroscope and orientation sensors live. On iPhone and iPad the browser will ask for Motion & Orientation permission first.
- Alpha
- —°
- Beta
- —°
- Gamma
- —°
- X
- —
- Y
- —
- Z
- —
Quick guide: how to use the Sensor Test
Takes under a minute- 1Open this page on a phone or tablet with motion sensors.
- 2Tap Run test and allow motion access on iOS when prompted.
- 3Tilt and rotate the device and watch the values change.
- 4Flat zeros usually mean a desktop machine or a blocked permission.
Overview
Phones and tablets are packed with tiny motion-sensing chips that most people never think about, yet they're doing constant work behind the scenes: rotating your screen when you turn the device, powering step counters, letting racing games steer by tilt, and feeding augmented reality apps a sense of where the camera is pointing in physical space. This tool gives you direct, live access to those same readings through your browser, no app install required.
It reads three main sources: the accelerometer, which measures linear acceleration (including the pull of gravity) along the X, Y and Z axes; the gyroscope, which measures rotation rate around those same axes; and orientation events, which fuse accelerometer, gyroscope and often magnetometer data into an easier-to-read alpha, beta, gamma angle set describing which way the device is facing. Where available, a raw magnetometer reading (compass heading) is shown too.
None of this works meaningfully on a typical desktop or laptop computer, because that hardware simply isn't installed in most of them. If you're testing on a phone, make sure you grant the motion and orientation permission prompt when asked, particularly on iOS, where Apple requires an explicit tap before any of this data is released to a webpage.
How to read your results
Accelerometer (X, Y, Z)
These three numbers describe acceleration in meters per second squared along each axis. Lay the phone flat on a table, screen up, and the Z axis should read close to +9.8 (or -9.8 depending on sign convention), representing gravity pulling straight down through the device. Tilt or shake it and you'll see the X and Y values jump as you introduce sideways and forward-back acceleration.
Gyroscope (rotation rate)
Reported in degrees per second (or radians per second, depending on the browser), this tells you how fast the device is currently spinning around each axis, not its absolute angle. Hold the device still and these should sit near zero; rotate it smoothly and you'll see a proportional spike that returns to zero once you stop moving.
Orientation (alpha, beta, gamma)
Alpha is compass-style rotation around the vertical axis (0 to 360 degrees), beta is front-to-back tilt (-180 to 180), and gamma is left-to-right tilt (-90 to 90). These three numbers together fully describe which direction your device's screen is facing in 3D space, and they're what game engines and AR apps typically consume directly.
Permission state
A clear indicator shows whether sensor access has been granted, denied, or not yet requested. If it says denied, you'll need to reset site permissions in your browser settings and reload, since most browsers won't re-prompt automatically once you've said no.
Troubleshooting
If your sensors aren't reporting data, work through these steps:
- Confirm you're testing on a phone or tablet. Standard desktops and most non-convertible laptops have no motion sensors to read.
- Tap the enable-sensors button on the page and accept any permission prompt that appears, especially on iOS Safari, which requires this explicit gesture.
- Make sure the page is loaded over HTTPS. Motion and orientation APIs are blocked entirely on insecure HTTP pages in most modern browsers.
- If you previously denied the permission, open your browser's site settings for this page and reset the motion/orientation permission, then reload.
- Try a different browser. Firefox for desktop and some privacy-focused browsers disable the Generic Sensor API by default.
- Close other apps using the camera or AR features, since some platforms restrict concurrent high-rate sensor access.
Common causes of drift and unreliable readings
Gyroscope drift is one of the most frequently misunderstood sensor quirks. Because a gyroscope reports rate of rotation rather than absolute angle, any small measurement bias accumulates over time when you integrate it into a position estimate. Leave a device sitting still for several minutes while watching a gyroscope-only orientation estimate and you'll typically see it slowly wander even though the device hasn't moved. Manufacturers compensate for this with sensor fusion, blending gyroscope data with accelerometer gravity readings and magnetometer heading to periodically correct the drift, which is why most on-screen "orientation" numbers stay far more stable than the raw gyroscope alone.
Magnetometer readings can also be thrown off by nearby metal objects, magnets, speakers, or even a phone case with a magnetic clasp. If your compass heading seems consistently wrong by a fixed offset, try moving away from metal furniture, laptops, or other phones and see if the reading corrects itself.
Why sensor access requires permission
Motion data can reveal surprisingly personal information: your gait while walking, whether you're in a moving vehicle, even rough guesses at what you're typing based on how the phone wobbles in your hand. Because of this, browser vendors have steadily tightened access. Apple led the way by requiring an explicit permission prompt tied to a user tap since iOS 13, and other browsers have been moving in the same direction with the Generic Sensor API's permissions model. If a site could silently read your device's motion in the background with no consent, it would be a meaningful privacy leak, so the extra tap you have to make is a deliberate trade-off in your favor.
Frequently asked questions
Why does my desktop show no sensors?
Accelerometers, gyroscopes and magnetometers are physical hardware components found almost exclusively in phones, tablets, and some laptops with 2-in-1 or tablet modes. A standard desktop PC or non-convertible laptop simply has none of this hardware, so there is nothing for the browser to read.
Gyroscope test online shows all zeros, is that normal?
Zeros usually mean the browser hasn't been granted motion permission yet, or the page is sitting still and there's genuinely no rotation to report. Try tapping the enable-sensors button, granting the permission prompt, then physically rotating the device.
Why did iOS ask me to allow motion and orientation access?
Since iOS 13, Safari requires an explicit user gesture and a permission grant before any page can read the accelerometer, gyroscope, or compass. This was added to stop sites from silently fingerprinting or tracking devices through motion data. You must tap an on-page button, a background API call cannot trigger the prompt.
What's the difference between the accelerometer and the gyroscope?
The accelerometer measures linear acceleration along the X, Y and Z axes, including the constant pull of gravity when the device is still. The gyroscope measures rotation rate around those same three axes. Combined, they let the device calculate its orientation in space far more accurately than either sensor alone.
My orientation values seem to drift over time. Why?
Gyroscopes measure rate of rotation, not absolute angle, so any tiny reading error accumulates the longer you track it, a phenomenon called drift. Most devices correct for this by periodically re-referencing against the accelerometer and magnetometer, but pure gyroscope-only drift over many minutes is expected and normal.
Why is the magnetometer or compass heading unavailable?
Compass heading needs both the magnetometer and a fused orientation model, and several browsers (notably desktop Chrome and Firefox) don't expose raw magnetometer data at all for privacy reasons. It's most reliable on mobile Safari and Chrome for Android.
Can a website track me using motion sensors without asking?
On modern iOS this is blocked by the mandatory permission prompt. On Android Chrome, motion and orientation events are generally available without an explicit prompt over HTTPS, though this varies by Chrome version and is trending toward requiring the Generic Sensor API's own permissions model.
Does this sensor test work if my browser is in an iframe?
Many sensor APIs are blocked inside cross-origin iframes unless the parent page explicitly grants a Permissions Policy allowance for that sensor. If you've embedded this test somewhere, open it directly in its own tab instead.
Why do values update so fast and look jittery?
Raw sensor hardware is noisy by nature and most phones sample at 60Hz or faster. Small vibrations, hand tremor, and sensor noise floor all show up as constant tiny fluctuations. This is completely normal and doesn't indicate a faulty sensor.
My laptop has a 'tablet mode' but shows no sensors. What's wrong?
Not every 2-in-1 laptop actually ships with an accelerometer or gyroscope chip; some rely purely on a hinge-angle sensor for mode switching. Check your device's spec sheet, or try Windows' built-in Sensor Diagnostic Tool to confirm the hardware exists before assuming the browser is at fault.
Is there a way to test sensors on a browser that blocks them entirely?
Firefox desktop and several privacy-hardened browsers disable the Generic Sensor API by default. You'd need to test on Chrome, Edge, or Safari (mobile) to get live readings, or check the target browser's flags page for an experimental sensors toggle.