Fiddler

fiddler

Fiddler is a powerful web debugging proxy tool that captures and analyzes HTTP(S) traffic. It’s commonly used for debugging applications, inspecting web requests, and understanding how clients interact with servers.

Common Options

• --port: Specify the port Fiddler should listen on (e.g., --port 8888).
• --capture: Enable capturing HTTP(S) traffic.
• --no-capture: Disable traffic capture.
• --install-cert: Install the Fiddler root certificate for HTTPS decryption.
• --filter: Apply a filter (e.g., a regex) to narrow down the captured traffic.
• --save-sessions: Save captured sessions to a file for later analysis (e.g., .saz file).
• --no-ui: Run Fiddler without a graphical interface (headless mode).
• --verbose: Enable verbose logging to see more details about the traffic and internal processes.

Examples of Fiddler Commands

Here are some practical examples of how to use Fiddler with these options:

• Start Fiddler on port 8888:
  > fiddler --port 8888
  
• Capture traffic with a filter for a specific domain:
  > fiddler --capture --filter ".*example.com.*"
  
• Save captured sessions to a file:
  > fiddler --save-sessions "traffic.saz"
  
• Run Fiddler in headless mode without UI:
  > fiddler --no-ui --capture
  
• Inspect traffic with detailed logging:
  > fiddler --verbose
  
• Install the Fiddler root certificate for HTTPS decryption:
  > fiddler --install-cert

Summary

Fiddler provides a versatile way to capture and analyze web traffic, whether for debugging applications, security testing, or performance optimization. With options like filtering, saving sessions, and headless mode, it adapts to a wide variety of use cases.