Online Compass
Two north references can produce different numbers
Geographic north is the direction toward the geographic North Pole. A magnetic compass follows the local horizontal magnetic field. The angle between magnetic and geographic north is called magnetic declination.
Declination depends on place and time. A correction copied from another location or an old diagram may not apply to your current situation. NOAA's World Magnetic Model is an authoritative model source; Online Compass offers an estimated True North mode using WMM2025 locally. Set the correction location first; the mode requires an explicitly magnetic sensor reference.
Read what the phone supplies
The device compass shows a separate north-reference line. An iOS compass report is labeled magnetic. A browser absolute orientation report is labeled as having an unspecified magnetic/true basis. Relative rotation is never labeled as a north heading.
These labels describe the information available to this tool. They do not certify the physical sensor or eliminate interference. Read the reported accuracy and check the direction independently when it matters.
If the browser omits an accuracy value, the page says so. Displaying a heading to the nearest degree describes its presentation; it does not establish that the hardware is accurate to one degree.
A route bearing starts with two places
The bearing calculator takes a start and destination. It estimates the initial direction clockwise from geographic north along a spherical great-circle route. A 90° result means an initial eastward bearing on that model, not a live reading of your phone's top edge.
Enter both coordinate pairs in the calculator. The result does not follow roads, terrain or obstacles.
Along a long great-circle route, the bearing can change as you travel. The initial number is the direction at the start, not a promise that holding one compass angle will trace the entire route.
Do not combine references silently
To compare a magnetic heading with a geographic bearing, you need a valid local declination value and the correct sign convention. The optional True North mode adds WMM2025 declination, with east positive, to a magnetic sensor heading. It refuses unspecified sensor references, weak-field zones and dates outside 2025–2029. The model does not improve sensor accuracy or remove nearby interference.
Do not add a guessed adjustment to make two displays agree. First check the selected points, the place and date of any external declination source, and the reference used by the other instrument. If its reference is unknown, agreement between numbers cannot prove that either one is correct.
Position, course and orientation are separate
A latitude and longitude identify a position. A geolocation travel heading, when available, describes motion. An orientation sensor describes the device's physical orientation. A stationary phone can point east without moving east.
Coordinates labels travel direction separately from a compass reading. The manual compass slider supplies a user-selected angle and has no north reference. Use the value that answers your task: position for where you are, a route bearing for where a chosen destination lies, and a supported sensor heading for which way the device is facing.