Sensors

Compass Test

Display a live compass heading from device orientation data and check how it responds when you turn.

Privacy: Heading data is processed locally. No location or orientation information is uploaded.

Test interface

Your browser may ask for permission after you press Start.
Ready. Enable the compass and turn slowly.
N E S W
— ° —
Heading—
Sensor source—
Compass readings can be distorted by magnets, metal, speakers and cases. The heading may be relative rather than true north depending on the browser and device.

How to use this tool

  1. Click Enable compass and grant motion permission if your browser asks.
  2. Hold the device flat and slowly turn in a circle.
  3. Compare the displayed heading with a known direction or a physical compass.
  4. Stop the test when finished.

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Technical explanation

The page reads DeviceOrientationEvent.alpha and, on iOS, webkitCompassHeading. It converts the value into a 0–360° heading and draws a compass dial. Some browsers only provide a relative orientation until an absolute orientation event is available.

Magnetic interference from speakers, metal desks, cases, and magnets can distort the reading. The browser may also apply smoothing. A phone compass is a navigation aid, not a surveying instrument, and it is not calibrated by this page.

Troubleshooting

The compass is unsupported

Desktop devices usually lack a magnetometer. Use a phone or tablet with a modern browser.

Heading is stuck or jumps

Move away from metal and magnetic objects, then wave the device in a figure-eight to help the system calibrate.

North is wrong

Check whether the reading is relative or absolute. Some browsers do not expose true north without a permission or sensor fusion.

Permission was denied

Reset motion access for the site and reload, then press Enable again.

Frequently asked questions

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