How to Use the Online Compass
The online compass reads your phone's built-in magnetometer through the browser — no app needed. Here is how to start it, calibrate it, and get a heading you can actually trust.
Troubleshooting
- No prompt on iPhone: Settings ▸ Apps ▸ Safari ▸ Motion & Orientation Access must be on. The page must be HTTPS (this one is).
- Needle stuck or 90° off: figure-8 calibration; remove magnetic cases; step away from cars and radiators.
- Heading drifts on Android: some browsers only expose relative orientation — the page tells you when that happens; Chrome usually provides absolute readings.
- Desktop: laptops rarely have magnetometers; the dial renders but cannot point. Use your phone.
Related: the compass corrects for magnetic declination automatically — hikers matching a paper map should know their map's declination date, since it drifts a little every year.
Moving vs standing still. While you are walking or driving, the heading you see is usually your GPS track — the direction you are actually travelling, derived from successive positions. Stand still and there is no track to derive, so the reading falls back to the magnetometer, which is the sensor that cares about nearby metal and needs the figure-eight calibration. A heading that was rock-steady on the move and jittery the moment you stopped is this handover, not a fault.
Step by step
- Open the compass page on your phone (compasses need motion sensors, so desktops show a demo dial only).
- Tap Start compass. On iPhone, approve the Motion & Orientation prompt; on Android it starts immediately.
- Hold the phone flat like a map, screen up, away from magnets — cases with magnetic clasps, car mounts and laptops all bend the reading.
- Calibrate by waving the phone in a slow figure-8 for a few seconds until the needle settles.
- Optionally allow location so the dial corrects from magnetic to true north using your local declination.
- Tap Focus mode for a clean, full-screen dial — Esc or the button exits.
Works offline · nothing leaves your device · magnetic → true north corrected with your local declination when location is allowed.