Basic about Fiddler

Overview

1. HTTP 
2. Requests 
3. Responses 
4. What is Fiddler? 
5. Why Use Fiddler? 
6. How does Fiddler Work? 
7. Where to get Fiddler? 
8. Basic Usage  

1. HTTP 

• HyperText Transfer Protocol
• Protocol defined in RFC 2068 (Http 1.1), January 1997 
• http://www.ietf.org/rfc/rfc2068.txt 
• Request/response paradigm 
• Header and body  

2.HTTP Request 

3.HTTP Response  

4.What is Fiddler? 

•  Freeware HTTP tracing tool 
•  Shows complete request and response (not packets)  
•  Created by Eric Lawrence (@ericlaw) 
•  Microsoft, Program Manager on IE team
•  First version 0.8, October 2003
• C# 

5. Why Use Fiddler? 

• Troubleshoot problems 
• Performance evaluation
• Fiddle with requests and responses 
• Security testing 
• Visualize page requests (timeline) 
• Periodic site reviews 

6.How Does Fiddler Work? 

•  Proxy 
•  Local 
•  Remote (smart phones, tablets, non-Windows platforms) 
•  Adjusts browser’s proxy configuration to intercept traffic 
•  Many of the latest browsers work with localhost and 127.0.0.1 (automatically) 
•  ipv4.fiddler or ipv6.fiddler 
•  NOT a wire/network monitor! 

7.Where to Get Fiddler? 

• http://fiddler2.com 

8.Basic Fiddler Usage 

•  Capture traffic 
•  Review “sessions” 
•  Statistics 
• Number of Requests 
• Bytes received 
• Chart  
• Timeline 
• Inspectors 
• Save as .saz file  

Summary 

•  HTTP protocol used to communicate between web browsers and web servers 
•  Fiddler is a great freeware tool that shows web requests and responses 
•  Fiddler acts as a proxy for browsers and even other platforms and devices 
•  Reviewed basic common usage of Fiddler