---
title: "Help — Online Compass"
description: "Start the device compass, understand its reference and accuracy, calibrate a drifting sensor, or use a manual angle."
canonical: "https://onlinecompass.lol/help"
---

Help

 

# Use the compass

 
 
- Open the [compass](https://onlinecompass.lol) on a secure connection and press “Start device compass.” Allow orientation access if your browser asks. 
- Hold your device nearly flat. Read the numeric heading, cardinal direction, north reference, and any accuracy estimate shown below the dial. 
- Compare the result with a known direction before using it. Move away from magnets, metal, and electronics if the heading seems wrong. 
 

## If the reading drifts

 

Move away from interference and follow your device's calibration instructions. A gentle figure-eight motion may help on some devices. Compare against a known direction afterwards; an animation or a steady reading cannot verify calibration. A larger reported uncertainty is a reason to check the reading, while a smaller estimate does not prove that it is correct.

 

## If sensors are unavailable

 

Permission may be denied, your browser may provide only relative rotation, or your device may have no suitable sensor. The page will explain the state. Choose “Use manual angle” to rotate an unverified marker with a mouse, touch, or arrow keys. Manual mode does not find north.

 

## Magnetic versus true north

 

iOS compass data is labeled magnetic. Other browser absolute data is labeled without claiming a magnetic or true reference. Choose “True North (estimated)” and set a location to apply a local WMM2025 declination correction to an explicitly magnetic sensor heading. The model does not improve sensor accuracy. See the [methodology](https://onlinecompass.lol/methodology) for details.