Detecting VPN & Proxy IPs: Tips & Tricks

If you want to anonymize your online activities, especially if you’re accessing the Internet from a public place or coffee shop, then you’ll need to make sure that your true IP address doesn’t leak out. 

Using a VPN or proxy server can help protect your identity online, but the problem with these services is that many of them don’t provide effective protection and some of them aren’t even legitimate. 

Here are three ways to detect VPN and proxy IPs so that you can verify their authenticity and trustworthiness before using them.

Run a WebRTC Test:

Although it is an older method, WebRTC for proxy detection is still quite useful. Direct peer-to-peer communication over UDP is made possible in browsers via the WebRTC (Web Real-Time Communication) method. Direct audio and visual communication between peers is supposed to be made possible.

Since direct peer-to-peer communication is feasible, a method for identifying the peers' internal and external IP addresses is required.

Perform an Open Ports Test:

Although this test may be a little invasive, it's rather simple to describe how it works: I run a nmap port scan if I have reason to believe that an incoming connection is from a proxy. 

I could also ping the host instead. The host is typically already a sign that it might be a proxy if it is up and reachable from the Internet. The majority of regular Internet users are protected by a carrier- or ISP-grade NAT, which prevents inbound connections from the Internet.

Well-known proxy ports like 3128 or 1080 being open on the host is a clear indication that a proxy server is in use.

Savvy proxy providers will block any inbound connections from random IP ranges, but perhaps some magic can be worked using an intrusion detection system and firewall bypassing using nmap.

Use a VPN Detection Tool:

The easiest one is to use a VPN and Proxy detection tool. They can provide up to 95 percent accurate information. These tools are mostly relied on their bots collecting and adding the public proxies to their databases. Those services can even catch private proxies or VPN IP's.

Go for an HTTP Proxy Headers Test:

In many HTTP proxy servers, you can find an additional HTTP header attached to each HTTEP request. And finding such headers means that a proxy server is being utilized.

The following sequence shows the presence of a proxy server:

var proxy_headers = ['Forwarded', 'Proxy-Authorization',

'X-Forwarded-For', 'Proxy-Authenticate',


'X-Requested-With', 'From',


'X-Real-Ip', 'Via', 'True-Client-Ip', 'Proxy_Connection'];


-Avoid using the same computer, network, or service provider to access sensitive information. Keep your use of those devices for a time when you are confident there are no security threats.

-Remember that open wireless networks make it easy for others to track your location and identity. When possible, try not to connect from public hotspots.

-Secure sites with HTTPS:// in the URL will be more secure than HTTP sites because they encrypt data between the site and the end user's computer.