When a detect IPs using VPN or proxy to the internet through a VPN or proxy, their IP address is hidden, and thus, they cannot be accurately identified. This is especially true if they use a free proxy or a public proxies such as the ones used in many iGaming casinos or by streaming services to unblock content that would otherwise be unavailable in their country.

The good news is that there are a number of ways to detect when a connection is using VPN or proxy. Most of these methods are based on IP characteristics and can be combined with other types of data such as user behavior analysis, fraud scoring or identity verification.

• Best Free IP and Proxy Check Tools for Quick Threat Detection

Detecting when a VPN or proxy is used is particularly important for businesses that sell products and services online or accept digital payments. These businesses may have strict regulations that require them to limit access if a customer’s location is outside of a specific geographic region. This type of restriction helps protect against fraud and ensures compliance.

A few of the most popular ways to detect a VPN or proxy are to look at DNS requests, compare the browser timezone against the IP, analyze protocol metadata (e.g. if a connection uses SOCKS), or look for mismatched header HTTP requests. In some cases, these techniques can also identify a VPN by identifying the operating system advertised by the user’s User-Agent and looking for a correlation with known open ports that are typically associated with proxy software.