The Geolocation API is a built-in browser interface that allows web applications to access the user's geographical location (with their permission). It provides two main methods: getCurrentPosition() for a one-time location fetch, and watchPosition() for continuous tracking. The API returns a GeolocationPosition object containing coordinates, accuracy, altitude, heading, speed, and a timestamp.

getCurrentPosition() fires once and returns the current location. watchPosition() registers a callback that fires every time the device position changes, returning a unique watch ID. Use clearWatch(id) to stop tracking. watchPosition is ideal for turn-by-turn navigation, fitness trackers, or any real-time location-based app.

There are three error codes:
Code 1 — PERMISSION_DENIED: The user denied the geolocation request (or the browser blocked it).
Code 2 — POSITION_UNAVAILABLE: Location information is unavailable (e.g., no GPS signal, hardware failure).
Code 3 — TIMEOUT: The request timed out before acquiring a location fix. The timeout threshold is set via the PositionOptions.timeout property.

The accuracy value (in meters) represents the radius of a confidence interval around the reported position. For example, an accuracy of 15m means the true position is likely within a 15-meter circle around the reported coordinates. Lower numbers indicate higher precision. GPS typically offers 5-30m accuracy, while Wi-Fi triangulation may be 20-200m, and cell tower triangulation can be 100m-5km.

Yes. Since Chrome 50+, all major browsers require a secure context (HTTPS) to access the Geolocation API. This protects user privacy by preventing man-in-the-middle attacks from intercepting location data. During local development, localhost is considered a secure context and the API will work without HTTPS.

Use this Geolocation API Simulator! Set custom coordinates, accuracy, and simulate various error scenarios. You can also use Chrome DevTools: open the Sensors panel (More Tools → Sensors), select a preset location or enter custom coordinates, and the browser will override its real geolocation. BrowserStack and physical device testing are recommended for production validation.