Day Pass Proxy Showing the Wrong City? What Is Going On

You bought a 4G day pass in Chicago. You open an IP checker. It says Illinois, or it names a city you have never thought about. A cheap line, a strange result, so the obvious worry is that you did not get what you paid for. You did. This page explains, in plain terms, why the city on a checker and the city of the modem are two different things, which of them websites actually care about, and the simple fix when the reading is wrong for the work you planned.

The short answer

Your SIM really is in the city you picked. The checker is not looking at the SIM. It is looking up your public IP address in a database, and that database records where the carrier connects your traffic to the internet. For mobile networks, that point is usually a regional hub. Sometimes it is in your city. Sometimes it is only known at state level. Sometimes it is a bigger city nearby.

IP addresses do not carry coordinates

An IP address is a number, not a pin on a map. Location lookups come from companies that build geolocation databases. The well-known ones are MaxMind GeoIP2, IP2Location, ipinfo and DB-IP.

They make their best guess from clues. Which region did the carrier register the address to? How is it routed? Has the network published a geofeed, a standard location file described in RFC 8805? How long do test signals take to reach it? What do apps report about the people using it? Put together, those clues point at a network hub, not at a building.

Your traffic leaves the carrier somewhere else

Here is the path. The modem in our rack talks to cell towers in your city. From the towers, the carrier carries your data across its own network to a regional gateway. At that gateway it goes through carrier-grade NAT, which means your public address is shared with lots of ordinary phones on the same network. Then it reaches the internet.

Because the public address belongs to the gateway, a database can only place it at the metro, the state, or the hub city next door. Nobody can give you a zip code or a street from a mobile address. If a mobile proxy seller promises zip-level location, be sceptical.

Carriers also group areas differently. In smaller markets one gateway may cover several states, so a rotation can land on an address filed under a different state. AT&T likes to gather traffic at a few large hubs. That is why an AT&T line can come up as a bigger city.

Our Boston lines show it plainly

We have Verizon and AT&T modems side by side in Boston, on the same towers. Look up a Verizon address from there and you get Boston. Check an AT&T one from that identical rack and New York comes back.

Same place, two answers, both normal. Regular AT&T customers in Boston see New York on their phones too, and they use their social apps and banking apps every day without trouble.

Why two checkers give two answers

Each database has its own sources and updates on its own timetable. One may know your range is in the metro; another may only be sure of the state. Carriers also move address ranges between markets, so the answer you get today can differ tomorrow, or after you rotate, with the modem sitting exactly where it was.

So do not trust one checker. Use two or three. A good first stop is the free tool for this on our Tools page. ipinfo is a good second opinion, and browserleaks shows several databases on one screen. Go with the answer most of them agree on.

Your browser can give you away too

Websites look at more than your IP. They see your browser's timezone and language. They can ask for your location through the HTML5 geolocation API, which uses your computer's GPS or Wi-Fi, not the proxy. WebRTC can show an address outside the proxy.

A US mobile address with a browser set to a timezone in Asia does not look right. GoLogin and Undetectable.io can set the timezone and location to match the proxy for you.

Moving around is fine. Sites expect a mobile address to shift within a carrier's network, just like a person who takes a trip. What looks wrong is one account active in two places at the same time.

What to do with your day pass

A day only has so many hours, so sort this out first:

• Before buying, ask yourself: do I need the exact metro, or is the right state good enough?
• As soon as the line is live, check it on two or three lookups
• Match your browser timezone and language to the result
• Reading wrong for the task? Pick one of our other seven cities for the line in the dashboard, at no charge
• Or write to support: they know which carrier in your city comes up as the city

Frequently asked