Phone sensors give approximate readings. Don’t rely on them for navigation, construction or anything where safety depends on the result.
An online compass that reads your phone's magnetometer and shows the heading in degrees and as a direction such as NE. Hold the phone flat to follow the top edge, or upright to follow the back camera. Tap True north to correct for magnetic declination using the WMM2025 model for your location.
How to use
- Hold the phone flat in front of you, screen up, away from metal and magnets. The heading of the top edge is shown in degrees and as a direction.
- Held upright, the compass follows the direction the back camera points.
- Tap True north to correct for magnetic declination. Your location is read once to compute it with the World Magnetic Model and is not sent anywhere.
- If the reading jumps or the accuracy is poor, move the phone in a figure 8 a few times to recalibrate it.
- On iPhone and iPad tap Allow motion sensors first.
- Without True north the heading is magnetic. Magnetic declination is the angle between magnetic and true north; in 2026 it is about −9° in Seoul, +13° in San Francisco and between 0° and +5° across much of Western Europe.
- Declination comes from the World Magnetic Model WMM2025 (NOAA and the British Geological Survey), valid 2025–2030 and accurate to about half a degree in most places.
- Phone compasses are typically within 5° when calibrated. Cases with magnets, laptops, cars and steel structures can throw them off much more. Don’t rely on a phone compass for navigation where safety matters.
- Some desktop and older browsers don’t give an absolute heading at all. In that case you see a simulated demo.
Magnetic north and true north
A compass points to magnetic north, which is not the same as true (geographic) north. The difference, called magnetic declination, depends on where you are and changes slowly over the years. In 2026 it is about −9° in Seoul, +13° in San Francisco and between 0° and +5° across much of Western Europe.
With True north on, the app reads your location once and computes the declination with the World Magnetic Model WMM2025 from NOAA and the British Geological Survey, valid from 2025 to 2030 and accurate to about half a degree in most places. Your location is not sent anywhere.
Getting a reliable reading
Phone compasses are usually within about 5° once calibrated. Keep the phone away from magnets, laptops, speakers, car dashboards and steel structures, which can bend the reading by tens of degrees. If the heading jumps or the accuracy shows as poor, move the phone in a figure 8 a few times. Many magnetic phone cases and mounts disturb the sensor; take the phone out if the reading looks wrong.
Frequently asked questions
Is the online compass accurate?
Typically within about 5° after calibration, away from metal and magnets. Don't rely on it for navigation where safety matters.
What is the difference between magnetic north and true north?
Magnetic north is where a compass needle points; true north is the direction of the North Pole. The angle between them is the magnetic declination.
How do I calibrate my phone's compass?
Move the phone slowly in a figure 8 a few times, rotating it in all directions, away from metal objects.
Why does the compass not work on my laptop?
Most laptops and some desktop browsers have no magnetometer or don't give an absolute heading. In that case a simulated demo is shown.
Does the compass need internet or GPS?
The heading comes from the phone's sensors alone. True north reads your location once to compute the declination.