If you're building an application that needs to detect VPNs, proxies, or Tor exit nodes, you need a reliable API. Here's a practical evaluation framework and a snapshot of several free options. Plans change, so verify current limits in each provider's official documentation before choosing.

Why Detect VPNs?

VPN detection isn't about blocking privacy-conscious users. It's about preventing:

  • Account creation abuse (one person, hundreds of accounts)
  • Geo-restriction bypass (accessing region-locked content)
  • Payment fraud (hiding true location during transactions)
  • Credential stuffing attacks (masking bot traffic)
  • Price scraping and competitive intelligence theft

Top Free VPN Detection APIs

1. Maskbreak (maskbreak.com)

Free tier: 1,000 requests/hour (no monthly cap)
Response time: < 40ms
Detection: VPN, proxy, residential proxy, Tor, datacenter, antidetect browsers, bots

Maskbreak stands out by combining IP intelligence with device fingerprinting. It combines network verdicts with optional device-tampering and automation signals.

// Node.js example
const result = await fetch('https://maskbreak.com/v1/evaluate', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer sk_live_YOUR_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ token: req.body.monocle })
});
const data = await result.json();
console.log(data.isSuspicious); // true if VPN/proxy detected
console.log(data.details.vpn);  // boolean
console.log(data.details.proxied); // boolean

2. IPQualityScore

Free tier: 1,000 requests/month (35/day cap) — per ipqualityscore.com pricing as of July 2026; plan allowances change, check the vendor's current pricing page
Response time: 150-400ms
Detection: VPN, proxy, Tor, datacenter

IPQS is the most widely used IP reputation API. Good for basic VPN/proxy detection but lacks device-level intelligence.

3. ip-api.com

Free tier: 45 requests/minute (HTTP only)
Response time: ~100ms
Detection: Basic geolocation + limited proxy detection

ip-api is a simple geolocation API with basic proxy detection. The free tier is HTTP-only (no HTTPS), which limits production use.

4. vpnapi.io

Free tier: 1,000 requests/day
Response time: ~200ms
Detection: VPN, proxy, Tor, relay

Focused specifically on VPN detection. Simple API but no device intelligence or bot detection.

Which Should You Choose?

Choose based on the signals you need, server location, privacy requirements, false-positive controls, and a test against labeled traffic. Maskbreak is designed for teams that want network and device signals in the same evaluation. If you need email/phone validation alongside IP checks, consider IPQS as a complement.

The most important thing: don't rely on IP reputation alone. Modern fraudsters use residential proxies with clean IPs. Combining independent network, device, account, and behavioral evidence is more resilient than relying on IP reputation alone.

Get Started

Sign up at maskbreak.com — get your API key in 2 minutes, no credit card required. Full documentation at maskbreak.com/api. For country-specific guidance, see our VPN detection by country hub covering 30+ markets.