Read the guide: How accurate is a phone vibration meter?
How to test your phone's accelerometer
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Step 1: Open this page on your phone in Safari, Chrome, Samsung Internet or Firefox. On a computer, scan the QR code to open it on your phone.
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Step 2: Lay the phone flat, screen up, on a solid table and tap Start. On iPhone or iPad, tap Allow when Safari asks for Motion & Orientation access.
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Step 3: Leave it still for 10 seconds. One axis should read about 9.8 m/s² (1 g) and the other two close to 0.
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Step 4: Check the sample rate. About 60 per second is normal. The highest frequency your phone can measure is half of that, about 30 Hz.
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Step 5: Pick the phone up and tilt it slowly onto each edge. The 9.8 should move from one axis to another. That shows all three axes respond.
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Step 6: Give the phone a gentle shake. All three numbers should jump, then settle again when you stop.
This accelerometer test online shows the raw numbers your phone’s motion sensor sends to the browser. It’s the quickest way to find out whether the sensor works before you use the other vibration tools on this site. It also shows what your phone can and can’t measure.
What the online accelerometer test shows
The x, y and z readings
The accelerometer measures acceleration in three directions, in meters per second squared (m/s²). With the phone lying flat, screen up:
- x runs side to side across the screen.
- y runs from the bottom of the phone to the top.
- z points straight out of the screen.
These are raw readings with gravity included. So a phone lying still reads about 9.8 m/s² on z, which is 1 g. Some phones show it as −9.8. The sign depends on the phone and browser, not on a fault. A value a little off, like 9.7 or 9.9, is normal too. Small offsets don’t affect vibration readings, because the vibration tools remove gravity before they measure.
Sample rate and the 30 Hz limit
The sample rate is how many readings reach the page each second. Most phones deliver about 60. The highest frequency you can measure is half the sample rate, so about 30 Hz (1,800 RPM). The test shows your phone’s exact numbers.
Anything that shakes faster than that limit can’t be measured directly. It can even show up as a false, slower frequency. This is called aliasing. It’s why the vibration tools warn you when “the main vibration may be faster than your phone can measure.”
Sensor noise
Even on a still table, the numbers jitter a little in the second or third decimal place. That’s sensor noise. The vibration tools measure it during a 2-second “Hold still…” step and subtract it, so the phone’s own jitter isn’t counted as vibration. The car, motorcycle and ceiling fan tests skip this step.
A working phone lying still on a solid table settles into a small, steady jitter. If the numbers keep jumping while nothing nearby moves, try a heavier table away from appliances and busy rooms. If they still jump, restart the browser and test again.
Common causes and fixes
If the numbers stay blank or never change, work through these in order.
iPhone or iPad: motion access is off
Safari asks for Motion & Orientation access after you tap Start. If you tapped Don’t Allow, the browser remembers that until you close it. Swipe Safari (or Chrome, Edge…) away in the app switcher, open this page again, tap Start and choose Allow.
The page opened inside another app
Links opened inside social media or chat apps use a built-in browser that may block motion sensors. Open the page in Safari or Chrome instead.
Android: motion sensors are blocked
In Chrome, open Settings, then Site settings, then Motion sensors. Make sure this site isn’t on the blocked list.
The sample rate is low or uneven
If the rate is well under 60, close other tabs and apps and keep the screen on. Firefox on Android sends only about 10 readings a second, so use Chrome or Samsung Internet for the vibration tools. A lower rate lowers the highest frequency you can measure, and faster shaking can then show up at a false, lower frequency.
Still nothing
Restart the browser, then the phone. If one axis never changes while you tilt the phone, or all three stay frozen at 0, the sensor may be faulty. Try another phone on this page before you pay for a repair.
What this tool can’t measure
- Anything faster than about 30 Hz. Motor hum, bearing noise and engine vibration at high revs are too fast for a phone in a browser.
- Calibrated values. Phone sensors aren’t calibrated like lab accelerometers. Treat every reading as a good guide, not a certified measurement.
- Very small vibrations. Shaking weaker than the phone’s own noise won’t show up.
- Speed or distance. The sensor measures acceleration only. Speed and distance must be calculated from it, and small errors add up fast.
To see how close a phone gets to a real vibration meter, read how accurate a phone vibration meter is. Once your sensor checks out, measure something real with the vibration frequency analyzer.
Frequently asked questions
How do I know if my phone's accelerometer is working?
Lay the phone flat and still. A working sensor shows about 9.8 m/s² on one axis and close to 0 on the other two, with a little jitter. Tilt it and the 9.8 should move between axes. If the numbers never change, the sensor is blocked or faulty.
Why does it show 9.8 when my phone isn't moving?
That's gravity. The accelerometer feels the pull of the earth as a constant 1 g, about 9.8 m/s². The vibration tools on this site remove it, so they only see the shaking.
Why is the sample rate only about 60 per second?
Browsers limit how often they pass motion data to a web page, usually to about 60 times a second. The sensor chip can often run faster, but a web page can't get those extra readings. That's why the tools here measure vibration up to about 30 Hz.
Does this test work on a laptop?
Most laptops and desktops have no motion sensor, so the page shows a QR code instead. Scan it to open the same test on your phone. You can also tap Try demo to see how it works with demo data.
Is my sensor data sent anywhere?
No. Your readings stay on your phone and are never uploaded. There's no app to install and no signup.
Last updated .