Once a user grants permission, Geolocation provides access to geographical location information from device.
This HTTPs-only API exposes the navigator.geolocation object with a couple of useful methods:
- .getCurrentPosition(successCallback, [errorCallback, options])- "one shot" position request
- .watchPosition(successCallback, [errorCallback, options])- Watch a position and get notified of any changes.
- .clearWatch(someId)- allows you to stop watching for location changes.
No location information is made available through this API without the user's permission.
Request the user's current location. If the user allows it, you will get back a position object.
navigator.geolocation.getCurrentPosition(position => {
  const { latitude, longitude } = position.coords;
  // Do something cool with latitude, longitude
});Request the ability to watch user's current location. If the user allows it, you will get back continuous updates of the user's position.
const watchId = navigator.geolocation.watchPosition(position => {
  const { latitude, longitude } = position.coords;
  // Do something cool with latitude, longitude
});Finally, stop watching the user's location.
navigator.geolocation.clearWatch(watchId);You can also easily treat GeolocationPosition objects as JSON:
async function sendPosition() {
  try {
    // Get the current position
    const position = await new Promise((resolve, reject) => {
      navigator.geolocation.getCurrentPosition(resolve, reject);
    });
    // .stringify() calls .toJSON() automatically
    const body = JSON.stringify(position, null, 2);
    // Prepare the fetch request options
    const options = {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body
    };
    // Send request
    await fetch('https://example.com/api/positions', options);
  } catch (error) {
    console.error('Error getting or sending position data:', error);
  }
}
sendPosition();The specification provides examples covering different use case.