Behind "This Content Is Not Available in Your Region"
Have you ever accessed a foreign video site only to see "This video is not available in your region"? Websites can determine your country and city with considerable accuracy. How do they do it?
What Your IP Address Reveals
When you visit IP Check-san, your IP address is displayed. From this IP address alone, the following information can be roughly determined:
- Country: Identifiable with nearly 100% accuracy
- State/Prefecture: Approximately 90% accuracy
- City: Approximately 50-80% accuracy (more accurate in urban areas)
- ISP (Provider): Nearly 100% accuracy
Since IP addresses are assigned by ISPs, referencing a database of which IP address ranges each ISP assigns to which regions reveals the approximate location. MaxMind's GeoIP database is the most widely used. For a deeper look at how these databases work and their accuracy limitations, see our article on GeoIP location technology.
However, what an IP address reveals is the location of the "ISP's connection point," not your home address. Discrepancies of several kilometers within the same city are normal.
GPS - Smartphone Location Data
Smartphone location data is far more precise than IP address-based geolocation. Managing which apps can access this data is a key part of mobile privacy.
- GPS: Determines position using satellite signals. Accuracy of about 3-5 m. Most accurate outdoors
- Wi-Fi positioning: References a database of nearby Wi-Fi access point locations. Accuracy of about 15-40 m. Works indoors
- Cell towers: Estimates position from connected base station locations. Accuracy of about 100 m to several km
- Bluetooth beacons: Enables positioning within a few meters inside commercial facilities
Smartphones combine these methods to provide high-precision location data both indoors and outdoors.
Why Websites Use Location Data
- Regional content restrictions: Movie and music distribution rights differ by country, so Netflix and Spotify use IP addresses to determine the country and restrict content
- Automatic language switching: Access from Japan shows Japanese; access from America shows English
- Location-relevant information: Automatically displaying weather forecasts, nearby restaurants, and local news
- Ad targeting: "Show ads for Shibuya stores to users in Shibuya"
- Fraud detection: Detecting and alerting on logins from unusual countries
How to Hide Your Location
- VPN: By routing through a server in another country, you can change your IP address-based location
- Deny browser location requests: When a website requests location access, choose "Deny." GPS data won't be shared
- Turn off Wi-Fi: Prevents Wi-Fi positioning, though convenience decreases
IP Check-san displays the country and ISP information estimated from your IP address. If you're using a VPN, the VPN server's location will be shown.
Summary
Websites estimate your country, city, and ISP from your IP address, while smartphones pinpoint your location to within meters by combining GPS, Wi-Fi, and cell towers. Location data is the foundation of many useful features, but from a privacy perspective, we recommend periodically reviewing which sites and apps you've granted location access to.