What Your IP Address Tells Websites
Your internet service provider gives you a public IP address. All the devices on your home network share that IP address, and your address is unique on the internet.
When you connect to a website, that website then sees your IP address. Your computer connects to the website’s IP address, and the website sends data back to your IP address. Packets are transmitted through network routers, and the IP address on those packets tells the routers where they need to go.
However, websites can’t trace that unique IP address to your physical home or business address. Instead, websites can tie your IP address to your internet service provider, city, region, and even possibly your ZIP code. This is why you see ads for local businesses in your area online, for example.
For instance, if you go to a website like this IP Location Finder, you’ll see that the website can use your IP address to determine the name of your internet service provider, along with your local city, region, and country.
But that’s all the information websites can get. They don’t know your physical address within that city or region.
While this usually works well, it isn’t perfect. Websites may sometimes think your home IP address is in a different city from the one you live in, for example.
Websites Can Ask for Your Precise Location
Websites can sometimes see your precise physical location, but they have to ask you first. When a website asks for your location, modern web browsers show a permission prompt.
For example, a weather website may want to show you the weather down to your precise location, or a retail store’s website might want to show you all its nearby stores and their precise distance from your location. A mapping website could use your physical location to provide navigation directions and so on.
When a website wants this access, you’ll see a prompt in your browser asking for it. If you give the website permanent access to your location, it can always see your location without having to ask again whenever you load the website in your browser.
To check which websites can see your location, you’ll need to check your browser’s settings. For example, in Chrome, click Menu > Settings > Site Settings > Location. You’ll see a list of websites that are allowed to see your location under the “Allow” heading.
You’ll also see a placemark indicator in Chrome’s address bar when a website has accessed your location. Other browsers work similarly, providing a visual indication that this has occurred on the current page.
How Your Devices Can Find Your Precise Location
If you use a phone or tablet with a built-in GPS radio, your precise location is determined using GPS, and then provided to the website. That’s how it works with location services in apps on iPhone, iPad, Android, and even some Windows 10 tablets.
But what if you’re just using a computer? Well, your device can use Wi-Fi-based location services. By scanning for a list of nearby Wi-Fi networks and their relative signal strengths, your precise location can be estimated and then provided to the website if you choose to allow it. This same feature is used on mobile platforms when there isn’t a solid GPS signal.
And what if you’re using a computer without a Wi-Fi radio—in other words, just a PC plugged into an Ethernet cable? In this scenario, you won’t be able to give a precise physical location to a website. If you try, you’ll just end up providing a more general location based on your IP address—likely just the city or area you live in.
Big Data and Cross-referencing Location Information
By the way, it’s technically possible for websites and advertising networks to cross-reference data. They might be able to tie your IP address to a physical address, for example.
For instance, let’s say that you have multiple devices on your network, and they all share a single IP address—the usual situation. Now, let’s say one device on the network goes to a particular website, which we’ll call “ExampleCorp,” and gives it access to your precise location. ExampleCorp now knows the current physical address associated with the IP address.
Now, let’s say that you head to the ExampleCorp on another device and deny it access to your precise location. ExampleCorp’s website may not act like it has your precise location. However, ExampleCorp knows your IP address, and it knows that the IP address was tied to a specific location.
We don’t know how many companies are tying this data together in this fashion. However, some websites and advertising tracking networks likely are. It’s certainly possible with the technology they have.
VPNs and Hiding Your Location
If you really want to hide your physical location from a website, you can use a VPN (virtual private network) Or, for additional privacy at the cost of speed, use Tor.
When you access a website through a VPN, you connect directly to the VPN server, and the VPN server connects to the website on your behalf. It functions as a middleman, passing traffic back and forth.
So, when you access a website through a VPN, the website will see that VPN’s IP address, but it won’t know your IP address. This is how VPNs allow you to bypass geographical restrictions on the web. If a website or streaming service is only available in the U.K. and you’re in the U.S., you can connect to a U.K.-based VPN and access the website. After all, the website thinks you’re connecting from the VPN’s address in the U.K.
RELATED: What Is a VPN, and Why Would I Need One?
