Browser GPS Tracking: How the Geolocation API Works
A plain-language guide to browser location requests, permissions, timestamps and the values a website may receive.
A browser-based GPS speedometer usually uses the Geolocation API. The page asks the browser for location updates, and the browser asks the operating system or location service for a position. The site does not directly control satellites, and the returned values depend on the device, permissions and environment.
A location response
A geolocation position can include latitude, longitude, an accuracy estimate, a timestamp and optional fields such as altitude, heading and speed. Optional fields may be null when unavailable. A robust website must handle missing values and permission errors rather than assuming every device returns every property.
One-time request versus continuous updates
A one-time request returns a position when available. Continuous tracking uses a watch that can report new positions until it is stopped. Continuous updates can use more battery and can be paused or throttled by browsers when the tab is hidden. A page should stop watches when tracking is no longer needed and avoid starting duplicate watches after repeated taps.
Permission and secure context
Browsers normally require a secure context, such as HTTPS, and user permission to expose location. The user can deny permission, revoke it later or set a site-specific choice in browser settings. A website cannot legitimately bypass those controls. If location fails, show a useful explanation and let the user retry after correcting settings.
What the API cannot promise
The API does not promise a particular satellite constellation, update rate, accuracy or availability. It also does not mean the page is offline or that no network request occurs elsewhere in the site. Read the site's privacy policy to understand which data stays in the browser and whether any coordinates are sent to external services.
Frequently asked questions
Does the browser read GPS satellites directly?
Usually the browser receives a location estimate from the operating system or location provider.
Can a website force location permission?
No. The user and browser control permission; the site must handle denial gracefully.
Technical references
These references explain the underlying browser and positioning concepts. They do not imply endorsement of this website.