Is detecting a VPN legal?

Yes. Checking the characteristics of an IP address you receive traffic from is standard practice for fraud prevention and licensing.

How do I detect VPNs automatically?

Use the VPN detection API: send GET /v1/vpn/{ip} from your backend and act on the verdict and score.

Does the free checker need an account?

No, the checker above is free to use. An account and API key are only needed to automate detection.

IPScanner

VPN Checker

How to Detect a VPN

Paste any IP address to check whether it is using a VPN, then learn the signals behind the verdict and how to automate detection at scale.

Overview

How can you tell if an IP is a VPN?

You can tell an IP is a VPN by checking it against known VPN provider ranges, looking at whether it lives in a datacenter or hosting ASN instead of a residential ISP, and weighing its reputation history. No single signal is conclusive on its own, which is why a good VPN check combines several. The checker above does this for you instantly; the sections below explain what it looks at.

Signals

The signals that reveal a VPN

Each one shifts the verdict, together they give a reliable answer.

Known provider ranges

The IP appears in published or harvested VPN server ranges.

Datacenter hosting

Consumer traffic from a hosting ASN is a classic VPN tell.

Geolocation mismatch

Stated location conflicts with other location signals.

Protocol fingerprints

Signatures linked to common VPN protocols.

Reputation history

Prior anonymising behaviour from the address.

Confidence scoring

A combined score expresses how certain the verdict is.

Next steps

From manual check to automation

One-off checks

Use the checker above for ad-hoc investigation of a single IP.

In your signup flow

Call the API to flag VPN signups before they become a problem.

In fraud rules

Feed the VPN score into your existing risk engine.

At login

Trigger step-up authentication on VPN logins.

More tools

Explore related detection tools

VPN Detection APIReal-time VPN detection API. Send any IP and get back whether it belongs to a commercial VPN, with a confidence score. Free tier, simple REST, fast global lookups.Proxy Detection APIDetect HTTP, SOCKS, residential and datacenter proxies plus Tor exit nodes from any IP with one REST call. Real-time proxy detection API with a free tier.Residential Proxy DetectionDetect residential proxies that disguise traffic as ordinary home connections. Real-time residential proxy detection by IP with confidence scoring and a free tier.Datacenter Proxy DetectionDetect datacenter and cloud-hosted proxies by IP in real time. Identify hosting ASNs used for proxying and scraping with confidence scoring and a free API tier.

Explore the Suite

Try Our Other Tools

VPN DetectionIdentify IPs that route through encrypted VPN tunnels to mask their real location.Proxy DetectionFlag HTTP, SOCKS, residential and data-center proxies plus Tor exit nodes.IP GeolocationMap any IP to country, region and city with ISP and timezone data.ASN DataLook up the Autonomous System Number and organization that owns an IP range.WHOIS InfoRetrieve registration and ownership records for domains and IP ranges.

FAQ

Frequently asked questions

No detection is perfect, but combining provider ranges, hosting analysis and reputation catches the large majority of commercial VPNs and returns a confidence score for the rest.

Why Choose IPScanner

Teams use IPScanner to tell real users apart from masked and automated traffic.

Accuracy you can measure

Verdicts come with a 0 to 100 confidence score, so you tune the threshold to your own risk instead of trusting one number.

Built to scale

The API runs on infrastructure sized for production traffic, with a 99.99% uptime target for business-critical use.

Data that stays fresh

We refresh VPN, proxy, and Tor lists continuously, so newly spun-up servers get caught quickly.

Easy to wire in

A plain REST API works with any language or framework. Most teams are live the same afternoon.

Documentation that's honest

Worked examples in curl, JavaScript, and Python, plus straight notes on what each signal does and doesn't mean.

People who know the domain

Support comes from engineers who work on IP detection every day, not a generic help desk.

Trusted By