VaneOnline Compass
Open this page on your phone, tap Start, and hold the phone flat. The dial turns with the phone's own magnetic sensor.
Tap Start. On iPhone, Safari asks for motion access first.
- Reference
- Magnetic north
- Accuracy
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Your heading never leaves your device: the compass is read in your browser.
How to use it
- Open vanedash.com/compass on a phone. Laptops and desktops have no compass sensor.
- Tap Start. On iPhone, allow motion and orientation access.
- Hold the phone flat, top edge pointing where you want a bearing. The number at the top of the dial is the direction the top of the phone points.
Magnetic north, not true north
A phone's compass senses the Earth's magnetic field, so this dial points to magnetic north. True north, the direction of the North Pole along a map's grid lines, differs by the magnetic declination, which depends on where you are and changes slowly over the years. In much of Europe it is a few degrees; in parts of North America it is around 15. Map work and long hikes need true north. Why your phone compass is wrong, and how to fix it covers declination and calibration.
If the dial is wrong
- Magnets: cases and wallets with magnets in them, magnetic car mounts, speakers and laptops all bend the reading. Apple notes that even earphone magnets can. Take the phone out of a magnetic case and step away from metal.
- Calibration: wave the phone slowly in a figure of eight, turning it through every direction, then try again.
- Inside a car or a building: steel frames distort the field. Readings outdoors, away from vehicles, are the ones to trust.
Sources
- Apple, webkitCompassHeading (degrees from magnetic north) and Use Compass on iPhone (magnetic interference).
- NOAA NCEI, World Magnetic Model and the declination calculator.