Understanding HTTP 403 Errors in Python vs. Burp Suite Responses

What will you learn?

In this comprehensive guide, you will delve into the perplexing scenario where making API requests using Python results in a 403 Forbidden error while the same request through Burp Suite returns a successful status code of 200. You will learn to diagnose, understand, and resolve such discrepancies efficiently.

Introduction to the Problem and Solution

When engaging in web scraping or consuming APIs with Python, encountering various HTTP status codes is common. One challenging situation arises when an identical request succeeds in tools like Burp Suite but leads to a 403 Forbidden error in Python scripts. The differences in how these tools handle requests, including headers, cookies, and server security measures, can be the root cause of this issue.

To tackle this problem effectively: – Understand HTTP requests and responses. – Analyze successful Burp Suite requests versus failing Python queries. – Identify key factors contributing to the discrepancy. – Adjust your Python script to mirror successful aspects of the Burp Suite request.


import requests

url = "http://example.com"
headers = {
    'User-Agent': 'Your User Agent',
    'Cookie': 'your=cookie; values=here;',
    # Add any other necessary headers observed from your successful Burp Suite request

response = requests.get(url, headers=headers)

# Copyright PHD


Replicating successful aspects of a Burp Suite request within your Python script is crucial for resolving the 403 Forbidden error. Headers play a vital role by conveying essential information to the server about the requester (user agent) and any session details (cookies). Omitting these details can lead directly to receiving HTTP 403 errors. By observing and including relevant headers from successful calls made via tools like Burp Suite or browsers, you enhance your requests calls for better compatibility.

  1. What does HTTP status code 403 indicate?

  2. HTTP status code 403 signifies that access to the requested resource is forbidden due to lacking proper authorization credentials or server-imposed restrictions.

  3. Why do servers return different responses for seemingly identical requests?

  4. Servers may evaluate additional criteria such as IP reputation checks, required header fields like User-Agent, or prior interaction cookies that are not immediately apparent.

  5. How can I view my browser’s sent headers during regular visits?

  6. You can utilize developer tools within modern browsers under the Network tab after initiating network activity.

  7. Can changing my IP address help bypass HTTP 403 errors?

  8. Changing your IP address might help overcome IP-based rate limiting issues but doesn’t directly address query composition-related causes.

  9. Is it ethical to modify my script’s Headers?

  10. While technically feasible for testing on systems you own or have permission for, unethical use could breach terms of service leading to potential legal consequences.


Resolving discrepancies between response statuses obtained from web servers using manual versus automated methods necessitates understanding both technicalities involved. By dissecting each element comprehensively and enhancing our knowledge base, we empower ourselves with valuable insights into troubleshooting API calls effectively in today’s interconnected digital landscape.

Leave a Comment