HTML5: Up and Running

Chapter 6. You Are Here (And So Is Everybody Else)

Diving In

Geolocation is the art of figuring out where you are in the world and (optionally) sharing that information with people you trust. There are many ways to figure out where you are—your IP address, your wireless network connection, which cell tower your phone is talking to, or dedicated GPS hardware that receives latitude and longitude information from satellites in the sky.

Ask Professor Markup

Q: Geolocation sounds scary. Can I turn it off?

A: Privacy is an obvious concern when you’re talking about sharing your physical location with a remote web server. The geolocation API explicitly states: “User Agents must not send location information to websites without the express permission of the user.” In other words, if you don’t want to share your location, you don’t have to.