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VPN Detection API

A VPN flag tells you how someone connected, not whether to let them in. Fidro's VPN detection API spots VPN, proxy, Tor and datacenter IPs in one REST call, weighs them against the email and location, and answers allow, challenge or block.

What is Fidro?

Fidro is a fraud detection API for developers. One call checks the email, the IP and the network, remembers what it has seen before, and tells your code to allow, challenge or block, so you stop fake signups and stolen cards without building your own scoring. The free plan covers 200 validations a month, no credit card.

The problem

Most VPN detection APIs hand back true or false and leave the judgement to you. But plenty of good customers use a VPN, and plenty of fraud arrives without one. So you end up writing the scoring logic yourself, then bolting on a second vendor for email checks and a third for location.

How Fidro fixes it

Fidro checks the IP against VPN, proxy, Tor, datacenter and bad-ISP lists, weighs it alongside the email address and the location, and returns one score from 0 to 100 with the reasons. One call, one answer, and the same integration covers the payment later.

What you get

VPN, proxy and Tor detection

Commercial VPNs, open proxies, Tor exit nodes and hosting ranges, from lists refreshed daily.

A weighted risk score

A VPN on its own rarely means fraud. Fidro weighs it against email risk, location mismatch and blocklists to give you one number you can act on.

Location matching

Send the country the customer gave you and Fidro compares it with the IP, graded by distance, so a neighbouring country counts for less than another continent behind a VPN.

<200ms
Average response
200
Free validations/mo
$0
To start

Keep exploring

Try the free checkers on a real address, read every field in the docs, or see how Fidro compares.

All features API documentation Free email checker Free IP checker Check if an IP is a VPN Compare Fidro

Frequently Asked Questions

What is a VPN detection API?
An API that takes an IP address and tells you whether it belongs to a VPN, proxy, Tor node or datacenter rather than a home connection. Fidro goes a step further and returns a weighted risk score with an allow, challenge or block recommendation, so you don't have to write the scoring logic yourself.
How accurate is VPN detection?
It works from lists of known VPN, proxy, Tor and datacenter ranges, refreshed daily. No IP-based method is perfect, because providers rotate addresses all the time, which is exactly why a single true or false is a poor reason to block someone. Weighing the network alongside the email and location is more reliable than any one check.
Should I block every VPN user?
Usually not. Plenty of real customers use a VPN for ordinary privacy reasons, and blocking them all costs you signups. Treat a VPN as one input: a VPN plus a disposable email plus a country mismatch is a very different story from a VPN on its own.
Can I detect proxies and Tor as well as VPNs?
Yes. The same call returns proxy, Tor exit node, datacenter and bad-ISP signals alongside VPN detection, so you don't need a separate lookup for each.
Is there a free VPN detection API?
Fidro's free plan includes 200 validations a month with no credit card, which is plenty to build and test an integration. There's also a free browser tool at /tools/vpn-detector if you want to try a few addresses before writing any code.
How do I use VPN detection for fraud prevention?
Call the API at signup with the email address and the IP, then act on the recommendation: allow, challenge or block. Because the score already accounts for the email and location, you're acting on the full picture rather than one signal.

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