Fiddler - The free web debugging proxy for any browser, system or platform. Fiddler web debugging proxy helps you record, inspect and debug traffic from any browser. Fiddler is a simple, yet highly reliable software solution that performs HTTP debugging by recording the traffic between the web and your machine. Fiddler can be used for multiple purposes, but its main aim is to assist users in testing web applications, by logging everything that goes on at every request.
Features:
Web Debugging
Debug traffic from PC, Mac or Linux systems and mobile devices. Ensure the proper cookies, headers and cache directives are transferred between the client and server. Supports any framework, including .NET, Java, Ruby, etc.
Performance Testing
Fiddler lets you see the “total page weight,” HTTP caching and compression at a glance. Isolate performance bottlenecks with rules like “Flag any uncompressed responses larger than 25kb.”
HTTP/HTTPS Traffic Recording
Fiddler is a free web debugging proxy which logs all HTTP(s) traffic between your computer and the Internet. Use it to debug traffic from virtually any application that supports a proxy like IE, Chrome, Safari, Firefox, Opera and more.
Web Session Manipulation
Easily manipulate and edit web sessions. All you need to do is set a breakpoint to pause the processing of the session and permit alteration of the request/response. You can also compose your own HTTP requests to run through Fiddler.
Security Testing
Use Fiddler for security testing your web applications -- decrypt HTTPS traffic, and display and modify requests using a man-in-the-middle decryption technique. Configure Fiddler to decrypt all traffic, or only specific sessions.
Customizing Fiddler
Benefit from a rich extensibility model, ranging from simple FiddlerScript to powerful Extensions which can be developed using any .NET language.
4.6.20172.31233 [07/20/2017]
- Fiddler installs per user now. Multiple installations can coexist on the same machine
- Minor fixes and improvements.
Homepage
Changelog
Download Page
Note: Fiddler 4.x and Fiddler 2.x are essentially the same code; Fiddler4 is compiled targeting .NET4 while Fiddler 2.x targets .NET2. Fiddler 2.x is no longer updated.