Online Compass
A free digital compass that uses your device sensors to show which way is north. Works on mobile phones and tablets.
Your device does not have orientation sensors. Enter a heading manually to see the compass direction:
How Online Compass Works
Online Compass is a free, browser-based digital compass that reads your phone's magnetometer through the DeviceOrientationEvent API and shows your heading in degrees plus the 16-point cardinal direction in real time. It needs no app install, works offline once the page has loaded, and never sends sensor data to a server. Updated 2026-08-26.
How to Use a Compass
A compass is one of the most fundamental navigation tools. Whether digital or analog, understanding how to read a compass heading is an essential outdoor skill that can help you find your way when GPS fails or batteries die.
Understanding Compass Bearings
A compass measures direction in degrees from 0 to 359. North is 0 (or 360) degrees, East is 90, South is 180 and West is 270. The 16-point compass rose adds intercardinal (NE, SE, SW, NW) and secondary intercardinal directions for more precision.
Magnetic North vs True North
Digital compasses (and magnetic compasses) point to magnetic north, which differs from geographic (true) north. This difference is called magnetic declination and varies by location. In some areas the difference can be 15 degrees or more. For precise navigation, you need to adjust for your local declination.
Compass Navigation Basics
To navigate with a compass, take a bearing to your destination, then walk following that bearing. Check your compass frequently and pick a landmark in line with your bearing to walk toward. When you reach that landmark, take another bearing and pick a new target. This technique keeps you on course even in poor visibility.
Digital vs Analog Compasses
Digital compasses in smartphones use a magnetometer sensor. They are convenient but can be affected by nearby electronics, metal objects and magnetic fields. For wilderness navigation, always carry an analog compass as a backup — it needs no batteries and works in any conditions.
When GPS Fails
A compass combined with a topographic map is your most reliable navigation system in the backcountry. GPS devices can lose signal in deep canyons, dense forests and during storms. Knowing basic compass and map skills is a critical safety practice for any outdoor enthusiast.
Online Compass Accuracy: Correcting for Magnetic Declination in 2026
An online compass reads magnetic north, not true north, so every heading it shows is off by your local declination until you correct it. The correction is one subtraction: true bearing = magnetic bearing + east declination, or magnetic bearing − west declination. Declination changes with both place and year, which is why the current World Magnetic Model epoch runs 2025–2030. Look up your exact figure by postcode or coordinates with the NOAA NCEI magnetic field calculator before you rely on a bearing for navigation.
Typical 2026 values to sanity-check your reading:
- Seattle, WA — about 15.5° east: a compass reading of 90° is a true bearing of roughly 105.5°.
- New York, NY — about 12.8° west: a compass reading of 90° is a true bearing of roughly 77.2°.
- London, UK — about 1.5° east, small enough to ignore on short day hikes.
- Sydney, Australia — about 12.7° east.
Over a 5 km leg, an uncorrected 12° error puts you roughly 1 km off target, which is the difference between hitting a trail junction and missing it entirely. Declination also drifts by up to 0.2° per year in some regions, so a figure copied off an old map sheet can be several degrees stale. Updated 2026-08-26.
Frequently Asked Questions
How does the online compass work?
This compass uses the DeviceOrientationEvent API to read your phone or tablet magnetometer sensor. It detects magnetic north and displays the heading in real-time. On desktop browsers without orientation sensors, you can enter a heading manually.
Why is my compass not accurate?
Compass accuracy can be affected by nearby metal objects, magnets, electronic devices and magnetic interference. Try calibrating by moving your phone in a figure-8 pattern. Move away from large metal objects for better accuracy.
Does the online compass work on desktop?
Desktop computers typically lack magnetometer sensors, so the live compass feature requires a mobile phone or tablet. On desktop, this tool provides a manual heading input and compass education.
What is magnetic declination?
Magnetic declination is the angle between magnetic north (where a compass points) and true geographic north. It varies by location and changes slowly over time. For precise navigation, you need to add or subtract your local declination from compass readings.
Can I use this compass without internet?
Once this page is loaded, the compass works without an internet connection. It uses your device hardware sensors directly. However, you need to load the page initially while connected.
How accurate is an online compass compared to a real compass?
On a calibrated modern phone held flat and away from metal, an online compass is typically accurate to within 2-5 degrees, which is close to a hand-held baseplate compass. The bigger error is magnetic declination: the reading points to magnetic north, so you must add east declination or subtract west declination to get a true bearing. Check your local value with the NOAA NCEI magnetic field calculator.
How do I convert an online compass reading to true north?
Use true bearing = magnetic bearing + east declination, or magnetic bearing - west declination. For example, a 90 degree reading in Seattle (about 15.5 degrees east in 2026) is a true bearing near 105.5 degrees, while the same reading in New York (about 12.8 degrees west) is near 77.2 degrees. Declination drifts slightly each year, so use a current figure rather than one printed on an old map.