Question 1

How does the online compass find north?

Accepted Answer

It reads your device's magnetometer through the browser's DeviceOrientation API (webkitCompassHeading on iOS, alpha + absolute orientation on Android). The needle points to magnetic north and the heading updates live as you turn.

Question 2

Why does the compass ask for permission on iPhone?

Accepted Answer

iOS Safari requires explicit permission before any web page can read motion and orientation sensors. Tap 'Enable Motion Sensors' and choose Allow — the data stays on your device and is never uploaded.

Question 3

The compass is inaccurate or jumpy — what should I do?

Accepted Answer

Move away from metal objects, laptops, speakers or magnets, then wave your phone in a figure-8 pattern to calibrate the magnetometer. Hold the phone flat and away from magnetic cases.

Question 4

Does the online compass work on a desktop?

Accepted Answer

Most desktop computers do not have a magnetometer, so the compass needs a phone or tablet. On a device without a sensor you will see a notice explaining that heading data is unavailable.