Using ModHeader to change IP address

Benefits of changing IP address?

Changing an IP address during web development can offer several benefits:

  1. Testing Geolocation: By faking an IP address from different locations, developers can test how their website behaves and responds to users from different geographic regions. This is particularly useful when building location-based services or targeting specific audiences.
  2. Load Testing: Simulating multiple IP addresses can help evaluate the performance and scalability of a website by simulating user traffic from various sources. It allows developers to understand how their website handles concurrent requests and identifies potential bottlenecks.
  3. Troubleshooting and Debugging: Faking IP addresses enables developers to simulate specific scenarios or user environments to reproduce and debug issues. This can be beneficial when addressing region-specific issues, network restrictions, or testing different user access levels.
  4. Security Testing: By spoofing IP addresses, developers can assess the effectiveness of their website's security measures. It helps identify vulnerabilities, such as IP-based authentication flaws or bypassing geographically restricted content.
  5. Local Development: During the development phase, faking IP addresses can enable developers to mimic production environments or external dependencies that are not accessible locally. This ensures accurate testing and reduces dependencies on external services.

Overall, faking IP addresses in web development provides a versatile toolset for developers to enhance testing, improve performance, troubleshoot issues, and strengthen the security of their websites.

What is X-Forwarded-For header?

The X-Forwarded-For (XFF) request header is a de-facto standard header for identifying the originating IP address of a client connecting to a web server through a proxy server.

When a client connects directly to a server, the client's IP address is sent to the server (and is often written to server access logs). But if a client connection passes through any forward or reverse proxies, the server only sees the final proxy's IP address, which is often of little use. That's especially true if the final proxy is a load balancer which is part of the same installation as the server. So, to provide a more-useful client IP address to the server, the X-Forwarded-For request header is used.

Using a VPN is the most effective way to truly change your IP address, but in many cases, you can fake your IP address quickly for free by changing the X-Forwarded-For header.


X-Forwarded-For: <client>, <proxy1>, <proxy2>

Elements are comma-separated, with optional whitespace surrounding the commas.



The client IP address

<proxy1>, <proxy2>

If a request goes through multiple proxies, the IP addresses of each successive proxy is listed. This means that, given well-behaved client and proxies, the rightmost IP address is the IP address of the most recent proxy and the leftmost IP address is the IP address of the originating client.

Changing X-Forwarded-For request header

Using ModHeader, you can easily modify the X-Forwarded-For header using the following steps:

  • Click on , and select Request header
  • Add X-Forwarded-For request header with a fake IP address.
  • Now visit your web server and check the logs to see if your server is blinding trusting the X-Forwarded-For header. If it is, you may want to update your web server to not blindly trusting X-Forwarded-For request header.
  • Note: ModHeader can change X-Forwarded-For header, but it will not hide your IP, and may not work on all servers. To completely change your IP, try using NordVPN .