// Anonymity checks

A proxy and VPN detection API for finding who is hiding their real location.

Proxies, VPNs and Tor all exist to make a connection look like it's coming from somewhere it isn't. One GET request tells you which kind of anonymity network an IP belongs to, whether it looks actively in use right now rather than just registered to a provider, and the hosting range behind it — so you can allow, challenge or block with actual evidence instead of a guess.

Start with 25 free credits Read the API docs

Try the Free IP proxy checker — no signup →

What a proxy & VPN check returns

Proxy

proxy

Whether the address is a known proxy server rather than a residential or business connection.

VPN & active VPN

vpn, active_vpn

Whether the address belongs to a VPN provider's range, and separately, whether a VPN tunnel looks actively in use on it right now rather than simply registered to one.

Tor & active Tor

tor, active_tor

Tor exit-node membership, and whether the address is currently routing live Tor traffic.

Bot status

bot_status

Whether the traffic pattern looks automated rather than human — VPN-hopping and credential-stuffing tools often show up here too.

Hosting provider

ISP, organization, ASN

The ISP, organisation and autonomous system behind the address. Datacentre and hosting ranges, rather than a home or mobile ISP, are one of the strongest tells that a connection isn't what it appears to be.

Fraud score

fraud_score

A single 0–100 score that folds every signal above into one number you can threshold on.

GET /api/v1/check?ip=198.51.100.42

request.sh

curl -H "Authorization: Bearer fn_your_key" \
  "https://fraudnova.com/api/v1/check?ip=198.51.100.42"

response.json

{
  "success": true,
  "data": {
    "fraud_score": 82,
    "proxy": true,
    "vpn": true,
    "active_vpn": true,
    "tor": false,
    "active_tor": false,
    "bot_status": false,
    "country_code": "NL",
    "ISP": "Example VPN Provider",
    "ASN": 64501
  },
  "credits_remaining": 4986
}

Where teams use it

Enforce geo-restricted content and licensing

Streaming rights, regional pricing and export-controlled content all depend on where a visitor really is. A VPN or proxy flag on the connecting IP is your cue to re-check location claims before serving territory-locked content.

Stop trial abuse via VPN-hopping

Someone burning through your free tier over and over looks like a fresh signup each time — until you notice every one arrives through a different VPN exit IP. Flag active_vpn plus a high score at registration and route it to review or a stricter verification step.

Filter datacentre ad traffic

Clicks and impressions arriving from hosting-provider ranges rather than home or mobile ISPs rarely convert. The ISP/organization/ASN fields let you separate real audience traffic from bot farms and click services running out of a datacentre.

Questions, answered.

What's the difference between the proxy, VPN and Tor flags? +

They flag three different kinds of anonymising infrastructure: proxy covers open and commercial proxy servers, vpn covers addresses belonging to VPN providers, and tor covers Tor exit nodes specifically. An address can trigger more than one — plenty of VPN ranges are also flagged as proxies.

What does active_vpn add over vpn? +

vpn tells you the address belongs to a VPN provider's range at all; active_vpn tells you whether a tunnel looks actively in use on it right now. A provider's range can sit unused between customers, so active_vpn is the sharper signal when you want to catch a VPN in use on this specific request.

Should I just block every VPN user? +

Usually not. Plenty of legitimate visitors use a VPN for privacy or because their employer requires one. Most teams challenge — extra verification, a review queue, a CAPTCHA — rather than hard-blocking on the vpn flag alone, and save an outright block for a high fraud_score or a live abuse signal.

Will this flag corporate VPNs as fraud? +

A corporate VPN can trigger the vpn or proxy flag, since technically it is one. That's a false positive for your purposes but not a wrong answer from the check — it's exactly why the flag is one input into a score and a decision, not an automatic block on its own.

What does a check cost? +

One credit per check, whatever the type. Credit packs are prepaid, there is no subscription, and credits do not expire. You start with 25 free credits after verifying your email.