A proxy detection endpoint is a server-side API that examines network packets to identify connections that might be using a proxy. It uses data points like URLs accessed, types of web content downloaded, and other HTTP-level metadata to detect proxies, VPNs, and other anonymization services.

Proxies are often used for web automation, to bypass CAPTCHA challenges or to hide their location from websites that log user IP addresses. This can lead to fraud, identity theft and other serious crimes. Detecting proxies and VPNs enables sites to take additional precautions, like requiring two-factor authentication or email verification, for logins. More info https://www.ipqualityscore.com/documentation/proxy-detection-api/overview

Advanced systems use Deep Packet Inspection (DPI) to inspect network traffic at a more granular level, looking beyond simple headers to detect patterns associated with proxies and VPNs. This includes analyzing encrypted traffic to identify tunneling protocols such as OpenVPN or IPSec.

Proxy Detection API: Identify Hidden and Masked Connections Instantly

Other methods include detecting DNS leaks by looking at the timezone of the client’s ISP DNS resolver or by comparing the server-side cached geolocation of an IP address with a browser’s reported timezone. Checking for headers that are known to be left behind by proxies and VPNs, such as X-Forwarded-For and User-Agent Anomalies, is another way to detect proxy usage.

For e-commerce and other sites that collect sensitive information, a proxy detection API can help ensure that users are not using a proxy or VPN when they make a transaction. This can protect against credit card fraud, identity theft and other serious crimes, while also enabling e-commerce platforms to provide better customer support by verifying that a user isn’t behind a VPN or proxy.