Compass

This tool uses your smartphone's built-in magnetic (orientation) sensor to show which direction your device is facing, as N/E/S/W and a heading in degrees (0-360°). No app install required — it runs right in your browser.

Tap Allow orientation access. On iOS, a permission prompt will appear. Once allowed, the dial rotates to match your device's actual heading, showing the degree value and direction (N/E/S/W). On Android and some other devices, it works immediately without a prompt.

The "north" a compass points to isn't the true geographic North Pole on a map (true north) — it's magnetic north, the direction Earth's magnetic field points. Magnetic north follows the flow of Earth's internal magnetic field and sits in a different location from true north; the gap between them (called declination) varies by location. In Korea, declination is known to run roughly 7-8 degrees west, so hiking or surveying that needs precise heading must correct for this offset. This tool displays the raw sensor reading without declination correction, as an everyday compass — for precision work, pair it with a dedicated compass or map app that applies declination correction.

A smartphone compass relies on a built-in magnetometer that measures magnetic field strength along three axes. Over time, or after sitting near metal or electronics, the sensor can pick up a slight "bias" that skews readings — a process called calibration corrects this. The most common method is to hold the phone and wave it in a figure-8 motion several times; this lets the sensor sample the field from multiple orientations and cancel out the distortion. If your compass seems off, try the figure-8 motion first.

Rebar in concrete buildings, appliances, speakers, even a laptop on your desk can create localized magnetic fields that throw off the sensor. As a result, the same device tends to show much larger error indoors than outdoors, and readings can swing wildly near elevators or metal cabinets. Honestly: this tool only starts reading the sensor after you tap "Allow orientation access" on iOS, and it won't work if permission is denied or on a device without a sensor (most desktop PCs). Sensor data is calculated and shown entirely in your browser and is never sent anywhere.

Handy for getting a rough sense of direction outdoors, checking room or furniture orientation indoors, or estimating where the sun will be — everyday direction checks.