How does Google Maps know my location?

It’s kind of creepy, isn’t it? It seems like no matter what device you are using, Google Maps and other sites seem to know your exact location. Desktop computers don’t have GPS chips so you have to wonder, right?

There are several simple, non-insidious ways that a web site can determine your location. The simplest is that your router has a public IP address that can be traced. If you go to whatismyipaddress.com or any other similar site, you’ll find that your home or office router can be identified with a series of four numbers. These four numbers are reported to any other web site that asks, that’s just how the web works. If they weren’t, then the site couldn’t supply you with any information.

By looking at your IP address and the connection you have to your internet service provider, it’s possible to get an astoundingly close match. Your internet service provider publishes the physical locations of its equipment and so, by measuring the time that it takes your home equipment to reach different pieces of equipment operated by your ISP, it becomes pretty easy to get a close match for your location.

Google, though, seems to do a bit more. While their processes are secret, it’s possible that they are doing one of two things, especially if you are logged in with your Google ID. They may be checking your smartphone’s IP address to see if it’s the same as the computer you’re using, and then using your smartphone’s GPS, or it’s also possible that they are logging the IP address you are using and comparing it to your known home or work address. Several people have commented that Google always seems to recognize a home or work location better than any other.

While this sort of thing may come off a little creepy (and it should) for now the information is being used benignly. On the other hand, it’s a little scary to think that this information could be used against you quite easily. Laws haven’t caught up with your device’s capabilities, so exercise caution when you’re browsing, and if you don’t want to be found… turn off your phone.