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Open-source alternative to Fiddler

Telerik Fiddler is a robust web debugging tool that allows users to monitor, manipulate, and replay HTTP/HTTPS traffic. It provides a wide range of features, including performance testing, web session manipulation, and security testing, making it a comprehensive solution for web development and debugging.

On the other hand, Requestly is an open source tool available as both browser extension and desktop app. It allows users to set up rules for modifying URLs, injecting scripts, and redirecting requests. It provides a broad range of functionalities, including the ability to manipulate both request and response data, making it a versatile tool for front-end developers.

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Comparing Requestly vs Fiddler

Requestly is a light-weight & open-source alternative to Fiddler that is available as both Browser extension & Desktop app.





Modify HTTP Headers & Responses

Replace URL

Desktop App

Browser Extension

Network Inspector

Session Recording

Performance Testing

No performance impact

Requestly is lightweight and doesn’t slow down your browsing experience. Our efficient implementation ensures that Requestly won’t drain your system’s energy and memory.

Active Support

We take pride in providing top-notch support to our users and helping them debug web applications faster. In fact, over 20% of our reviews mention our active support team!

Effortlessly collaborate

Collaborate with your teammates on Requestly rules to speed up debugging experience. Plus, the rules sync across devices so you can easily access all your rules from multiple machines.

Web debugger

A complete HTTP debugging software that works on your browser, simple & fast.

Modify API Response

Develop frontend without ready a backend or Modify existing API responses on production environment

Modify HTTP Headers

Add, Delete or Override Request & Response Headers

Redirect API and script requests

Redirect APIs/Scripts from one environment to another (e.g. Prod to Staging)

Insert Custom Scripts

Inject custom scripts/styles on external webpages for testing/demo purposes.

Simple & Secure API client for Front-end Developers

A comprehensive and web-based tool for modifying and testing APIs.

Import cURL Requests

Import your cURL requests easily from other API platforms

Send API Requests And Test Responses

You can customize request headers, query parameters, and request body payloads to test different scenarios.

History of API requests

Find the History of API Requests you made to debug them easily.

Frequently Asked Questions

Ready to get started?

What Fiddler is used for?

The tool enables you to inspect incoming and outgoing data to monitor and modify requests and responses before the browser receives them.

Is Fiddler free to use?

No, Fiddler has a free trial, after that you have to pay for the product.

Is Fiddler open source?

No, Fiddler is not a open source tool.

How much does Fiddler Cost?

Fiddler everywhere cost $10 per month per user.

Is Fiddler a proxy server?

Fiddler is a web-debugging proxy that monitors, inspects, edits, and logs all HTTP(S) traffic and issue requests between your computer and the Internet.