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Fiddler Classic

The Original and Free Web Debugging Proxy Tool Exclusively for Windows

The community-trusted free Windows-only tool that logs HTTP(s) network traffic.

Need cross-platform debugging? Download Fiddler Everywhere.

Your Big Wins Using Fiddler Classic

Satisfy Criteria

You have immense expectations in your role, and between experimental programming languages, security vulnerabilities, and coding errors, you need to be able to quickly get to the root cause of traffic and network problems.

Achieve Savings

Meeting these expectations without the proper tooling costs your company money and opportunities. Visualize how powerful you can become by spending less time searching for network errors and more time on useful things more aligned with your passion.

Make a Difference

Be the difference-maker in your role. Let Fiddler Classic give you and your team precious time back to deliver stable software by finding and resolving bugs/defects with speed and elegance.

What Can I Do With Fiddler Classic?

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Inspector in Fiddler Classic

  • Skillfully Inspect HTTP/HTTPS Traffic 

    Use Fiddler Classic to inspect HTTP/HTTPS traffic to and from browsers and desktop apps. The Traffic Inspector allows you to dive into the details of any specific network request.

  • Artfully Create HTTP(S) Requests 

    You can access everything you need to create a new request from the API Composer tab. Communicate with the web server with precision, thus calling only the resources you want.

  • Masterfully Mock or Modify Requests

    Mock services and help with testing behaviors triggered by responses from external providers. Use the AutoResponder to create mock responses and get closer to testing complete.


Hundreds of Thousands of Organizations Use Fiddler

Join these companies and the four million developers who are already building, running and debugging
with Fiddler.

Nasa microsoft fox
samsung ibm
continental airlines volvo

Looking to Get to Done Faster? Check out Fiddler Everywhere.

Try Fiddler Everywhere for Free, Then $12 a Month, Cancel Anytime.

Fiddler Everywhere works across all platforms equally well—macOS, Linux, and Windows—and gives you supercharged inspecting, debugging, and mocking features. And you can now enjoy the offline functionality.


Why Go with Fiddler Everywhere?

Use the world-class web debugging proxy tool that works seamlessly with any browser, application or process.
Leverage an improved and highly intuitive user interface along with enhanced organizational tools, and more powerful mocking capabilities.
Boost your performance with Fiddler Everywhere’s advanced and streamlined sharing and collaboration options.
Unlock sharing quotas and enjoy dedicated email support.
4.4 User Reviews

Fiddler is used by tens of thousands of Users daily and they love it! Don’t just take our word for it. G2 Users have consistently rated Fiddler 4.4 out of 5 stars. G2 is a renowned peer-to-peer review site that aggregates user reviews for business software.

Users of provide unbiased user reviews after they objectively access business software.