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Fiddler

Freemium
web debugginghttp proxynetwork analysisapi testingdeveloper toolhttps trafficpacket capturesecurity testingperformance

Fiddler is a powerful web debugging proxy that captures and analyzes all HTTP/S traffic between your computer and the internet, enabling developers to inspect, debug, and manipulate network requests.

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Fiddler is a long-standing and versatile web debugging proxy trusted by software developers, security researchers, and QA testers to analyze network traffic. It operates by intercepting and logging all HTTP and HTTPS communications, providing a detailed, real-time view of requests and responses from any application. Users can inspect raw data, set breakpoints to modify traffic on-the-fly, and simulate various network conditions for robust testing. Its core value lies in deep inspection capabilities, extensive customization through scripting, and a large ecosystem of add-ons that extend its functionality. While the original Fiddler Classic is Windows-only, the newer Fiddler Everywhere brings cross-platform support to macOS and Linux users.

Pros

  • Provides deep traffic inspection and on-the-fly manipulation of requests and responses.
  • Extensive scriptability using FiddlerScript (JScript.NET) for custom rules and automation.
  • Supports decryption of HTTPS traffic, providing full visibility into secure communications.
  • Fiddler Everywhere offers modern cross-platform support for Windows, macOS, and Linux.
  • The Fiddler Classic version is a powerful, feature-rich, and completely free tool for Windows users.
  • Can be configured to capture traffic from a wide range of devices, including mobile phones (iOS/Android) and game consoles.

Cons

  • The original and very popular Fiddler Classic version is Windows-only.
  • The UI for the cross-platform Fiddler Everywhere can feel less responsive and more resource-intensive than its classic counterpart.
  • Setting up HTTPS decryption requires installing a custom root certificate, which can be a complex step for beginners.
  • The learning curve can be steep for new users due to its vast feature set and technical nature.

Key features

  • HTTP/HTTPS traffic recording and analysis
  • SSL/TLS traffic decryption
  • Request and response composer for creating custom HTTP requests
  • AutoResponder for mocking API responses and testing edge cases
  • Performance analysis with statistics and timeline visualizations
  • Session archiving, comparison, and sharing
  • Extensible through a rich add-on ecosystem
  • Cross-platform availability with Fiddler Everywhere

Integrations

Google ChromeMozilla FirefoxMicrosoft EdgeWindowsmacOSLinuxiOS (via proxy settings)Android (via proxy settings)Visual StudioAny application using HTTP/S

Target audience

Web developers, software engineers, QA testers, security analysts, network administrators, and penetration testers who need to inspect and debug HTTP/S traffic.

Ratings & Reviews

0.0

Based on 0 reviews

Key Metrics

Active Users

Millions of users

Founded

2003

Headquarters

Sofia, Bulgaria

Pricing Tiers

Fiddler Classic

The original free web debugging proxy for Windows. Includes traffic recording, HTTP/S decryption, session inspection, and extensibility.

Free

Fiddler Everywhere Free

For individuals and learning. Includes basic debugging features, cross-platform use, but is limited to 20 saved sessions and basic collaboration.

Free

Fiddler Everywhere Pro

For professional individual use. Includes unlimited saved sessions, advanced filters, unlimited collaboration, and email support.

$12/mo

Fiddler Everywhere Enterprise

For organizations. Includes all Pro features plus SSO integration, automated user provisioning (SCIM), and dedicated support.

Custom

Frequently Asked Questions

Top Alternatives to Fiddler

Charles Proxy

A paid, cross-platform competitor often chosen for its polished native UI and strong focus on macOS/iOS development, though it lacks a free version.

Wireshark

A more powerful, lower-level network protocol analyzer that is ideal for deep packet inspection beyond just HTTP/S, but with a steeper learning curve.

Postman

While primarily an API client, its integrated proxy is a strong alternative for developers whose debugging work is focused exclusively on APIs.

Proxyman

A modern, native macOS/iOS debugging proxy with an intuitive interface, appealing to developers within the Apple ecosystem seeking a streamlined workflow.

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