This compass test reads the compass sensor in your phone and shows its heading on a turning compass card, the way a real compass works. Beyond the heading it measures how much the reading shakes while you stand still, counts sudden jumps that your phone's gyroscope did not feel (the mark of magnetic interference), and runs a circle check that finds how far off the compass is at every direction. It works in Chrome on Android phones and in Safari or Chrome on iPhone and iPad. On a computer, which has no compass sensor, the page shows a QR code to open the compass test online on your phone instead.
How to test your phone's compass
- Open this page on your phone, press Start compass and choose Allow if your iPhone asks to use motion and orientation.
- Hold the phone flat in front of you, screen up. The heading is the direction the top edge points. Held upright, it switches to the direction the back camera faces.
- Turn slowly on the spot. The card should turn smoothly, with no jerks.
- Point the phone along something whose direction you know, such as a straight street on a map, and compare the heading.
- Hold still for two seconds and read Wobble when still and Jumps.
- Press Circle check, then turn slowly through one full circle in about 20 seconds. Each ring segment turns green, yellow or orange for how accurate the compass is at that heading.
- Press Copy results if you want to keep the numbers.
What the readouts mean
| Readout | What it tells you | Normal result |
|---|---|---|
| Heading | The direction the phone points, 0 to 359 degrees from magnetic north | Matches a known direction within 5 to 10 degrees |
| Accuracy | How sure the phone is of its heading. Only iPhones report it | 15 degrees or better. A dash means calibrate |
| Wobble when still | How much the heading shakes while the gyroscope says the phone is still | Under 1.5 degrees |
| Jumps | Heading changes of more than 12 degrees with no matching turn | 0 |
| Tilt | How far the phone leans from flat | Under 25 degrees for a top edge heading |
| Readings | Compass updates per second | About 50 to 60 |
| Circle check | The biggest gap between compass and gyroscope over a full turn | Under 8 degrees good, 8 to 15 fair, over 15 poor |
The compass points the wrong way
When the heading is off by a steady amount, look for these causes, most likely first:
- A magnet near the phone. Magnetic cases and wallets, MagSafe accessories, car mounts with magnets and the clasp on folio cases all pull the compass. Take the phone out of the case and off any magnetic charger, and test again. A slow magnetic charger is a separate problem for the charging speed test. Metal plates for magnetic car mounts can also stop NFC working, which the nfc test checks.
- Metal and electronics close by. Laptops, speakers, steel desks, car dashboards and even reinforced concrete floors distort the field. Step a meter or two away, ideally outdoors.
- The compass needs calibrating. Calibrate it with the figure eight below, then run the circle check again.
- How you hold it. Flat, the heading follows the top edge. Upright, it follows the back camera. Tilting halfway between the two can swing the reading.
The heading jumps or drifts while you stand still
Jumps that the gyroscope did not feel mean something magnetic moved near the phone, or you walked past a strong source such as a car, a fridge door or an induction hob. Watch the Interference meter while you move the phone around: if it calms down a meter away, the compass is fine and the place is the problem.
If the heading creeps steadily in one direction while the phone lies still, the compass is uncalibrated or the sensor is faulty. Calibrate first. If the drift survives calibration, a restart, and a test outdoors away from metal, the phone needs a repair, especially after a drop or a screen or back glass replacement, since a stray magnet or a misplaced part during repair often upsets the compass.
How to calibrate your phone's compass
- Hold the phone firmly and draw a large figure eight in the air, three times, rolling your wrist so the phone faces different ways.
- On Android, open Google Maps, tap the blue dot showing your location and choose Calibrate, then follow the steps on screen.
- On iPhone, open Settings, then Privacy & Security, then Location Services, then System Services, and keep Compass Calibration switched on. Open Apple's Compass app and move the phone if it asks you to.
- Run the circle check again. A good result has no orange segments.
Magnetic north and true north
A phone compass senses the earth's magnetic field, so 0 degrees means magnetic north. Maps and GPS use true north, the direction of the North Pole. The difference, called magnetic declination, depends on where you stand and slowly changes over the years. Across most of the United States it is somewhere between 0 and 20 degrees, east in the west and west in the east. Look up the value for your location with the NOAA magnetic field calculator. Apple's Compass app can show true north: turn on Use True North in its settings, which newer iOS versions list under Settings, then Apps, then Compass.
Compass, GPS and gyroscope work together
Navigation apps combine three sensors. The compass gives the direction you face, the GPS gives your position, and the gyroscope smooths quick turns. If your blue dot is in the right place but faces the wrong way, the compass is to blame. If the dot itself wanders, run the gps tester. If games or 360 degree photos drift, the gyroscope test checks the motion sensor on its own. Walking and cycling directions often buzz before each turn, so if yours stay silent, run the vibration test.
What a browser compass test cannot measure
Browsers pass on the heading the phone works out, not the raw strength of the magnetic field, so this test spots interference from how the heading behaves rather than measuring the field itself. Only iPhones report an accuracy figure, and the test cannot calibrate the sensor for you: calibration happens inside the phone when you move it. The circle check relies on the gyroscope, so on the rare phone without one it cannot run. For the cleanest result, test outdoors, away from cars and buildings.
Compass test questions
How do I know if my phone's compass is accurate?
Run the circle check: hold the phone flat and turn slowly through a full circle. The gyroscope measures the turn on its own, so the test can tell how far the compass strays at each heading. Under 8 degrees all the way round is good. You can also stand on a straight street, check its direction on a map, and compare.
How do I calibrate my phone's compass?
Hold the phone and draw a large figure eight in the air three times, twisting your wrist as you go. On Android you can also open Google Maps, tap the blue dot and choose Calibrate. On iPhone, keep Compass Calibration switched on in Settings, Privacy & Security, Location Services, System Services.
Why does my phone's compass point the wrong way?
Usually a magnet or metal close to the phone: a magnetic case, a wallet with a magnetic clasp, a car mount, a laptop or a speaker. Move a meter away from them, calibrate with a figure eight and check again. If it is still off by the same amount everywhere, the compass sensor may need a repair.
Is the compass showing true north or magnetic north?
Phone compasses sense magnetic north, and maps use true north. The difference, called declination, depends on where you are: close to zero in the middle of the United States and more than 10 degrees in New England and the Pacific Northwest. The iPhone Compass app has a Use True North setting.
Can I run the compass test on a laptop?
Almost never. Laptops and desktop computers do not have a compass sensor, so the page shows a QR code that opens the test on your phone. Many tablets, including iPads, do have one.
Does the compass need internet or location access?
No. The compass is a sensor inside the phone and works offline. This page does not ask for your location, and nothing it reads is sent anywhere.