Geolocation API

Understand the topic

Geolocation requests the device location with user permission in an allowed secure context. Ask only when the visitor performs an action that needs location and explain the purpose. getCurrentPosition supplies coordinates through a success callback and reports failure through an error callback. Accuracy varies; a coordinate estimate is not proof of an exact address.

Worked example

if ("geolocation" in navigator) {
  navigator.geolocation.getCurrentPosition(
    ({ coords }) => console.log(coords.latitude, coords.longitude, coords.accuracy),
    (error) => console.log("Location unavailable:", error.message),
    { timeout: 10000, maximumAge: 60000 }
  );
}

Run this from a deliberate user action on your own HTTPS page or permitted local development context. The course preview sandbox intentionally does not request location permission.

Practice

Explain how the interface should behave if the visitor denies permission.

Show a clear message and allow manual location entry. Do not repeatedly prompt or prevent unrelated tasks.

Common mistake

Do not silently collect location on page load or assume sandboxed iframes have permission to use the API.

HTML documentation