Account takeover
Block credential stuffing and brute-force attacks before attackers gain access to legitimate accounts.
Proxy & VPN Detection
Unmask the network. Stop the abuse.
Identify traffic hiding behind proxies, VPNs and data centers.
Trusted by companies around the world
Stop attacks hidden behind anonymized networks
Geo-blocking
Prevent access from sanctioned or out-of-market regions and stay compliant by default.
Payment fraud
Detect high-risk transactions originating from atypical or mismatched geographies.
See the network behind the request
Every request is checked against an up-to-date database of proxies, VPNs, Tor exit nodes and hosting providers. CaptchaFox flags anonymizing infrastructure that's frequently used to mask abuse, scraping and account takeovers.
- Hosting & data-center detection — flag traffic from cloud and hosting providers that real users never come from.
- Proxy, VPN & Tor coverage — match every request against a continuously updated list of anonymizing networks and exit nodes.
Respond on your terms
Block residential proxies outright, challenge data-center IPs, or let legitimate VPN users pass through with a softer check. Tune the response per network type so you keep your real users happy.
- Per-network-type rules — block residential proxies outright while letting legitimate VPN users through with a softer check.
- Keep real users happy — tune responses so privacy-conscious visitors aren't punished alongside abusive traffic.
Use the signals without the widget
The Risk Intelligence API exposes the same proxy, VPN and hosting signals that power our widget as a standalone server-to-server endpoint. Score IPs from your own backend, enrich existing fraud pipelines or gate sensitive actions without changing the user experience.
- Standalone server endpoint — query the same network reputation data directly from your backend without rendering a widget.
- Drop into existing pipelines — enrich fraud, login or signup flows with proxy, VPN, Tor and hosting signals through a single API call.
Frequently asked questions
Everything you need to know. Can't find your answer? Contact our support team.
How does CaptchaFox detect proxies and VPNs?
Every request is checked against a continuously updated database of proxies, VPNs, Tor exit nodes and hosting providers. Network reputation is combined with behavioral and device signals, so anonymizing infrastructure is flagged even when it rotates.
Can I block proxies without blocking legitimate VPN users?
Yes. Policies are set per network type: you can block residential proxies outright, challenge data-center IPs and let privacy-conscious VPN users pass with a softer check.
Should I block all VPN traffic?
Usually not. Many legitimate users browse through VPNs for privacy, so blocking them outright costs real customers. A better approach is to challenge VPN traffic with a verification step while blocking the network types real users never come from, like data-center IPs and residential proxies.
What is a residential proxy?
A residential proxy routes traffic through real consumer devices and home IP addresses, making automated requests look like ordinary visitors. Attackers use them to evade IP blocklists, which is why CaptchaFox pairs network reputation with device and behavioral signals to catch them.
What is the Risk Intelligence API?
The Risk Intelligence API is a standalone server-to-server endpoint that exposes the same proxy, VPN, Tor and hosting signals that power the CaptchaFox widget. Use it to score IPs from your backend or enrich existing fraud pipelines without changing your user experience.
Take a look at our latest articles
Read CaptchaFox guides, case studies and insights on bot protection, spam prevention and account security.
May 5, 2026
New Intelligence APIs now available
Use the Intelligence APIs to evaluate incoming traffic before it reaches your application or server.
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April 22, 2026
What Is IP Geolocation? How It Works & Accuracy
Learn how IP geolocation maps IP addresses to physical locations, where accuracy breaks down, and why bot detection systems use it as one signal among many.
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April 15, 2026
What Are Residential Proxies? Bot Attacks & Detection
Learn what residential proxies are, how they work and how attackers take advantage of them.
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April 9, 2026
Best European CAPTCHA Solutions in 2026
Compare the top European CAPTCHA providers for 2026. Evaluate privacy, GDPR compliance, accessibility, and pricing to find the right fit.
Read nowFight bots and protect your users' data.
Don't give fraudsters and spammers a chance and protect your website with CaptchaFox today.
