27,766 flagged8 datasets
/16 subnet
181.121.0.0/16
Browse all /24 subnets inside this subnet, down to the individual addresses. Click on any /24 CIDR entry to jump to its address list.
00 · No key
Start without signing up.
Paste it into a terminal — no account needed. 1k daily allowance per user, answering ip and is_vpn.
curl "https://api.vpndetection.io/45.83.91.1"
{"ip": "45.83.91.1","is_vpn": true}
01 · Free key
Signup for 50k req/month.
No card, no sales call — the key is issued on signup.
Every request flags VPN IPs.
Upgrade only when you outgrow the allowance.