The best Web Debugger alternative to Fiddler is mitmproxy, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Fiddler and 15 are Web Debuggers so hopefully you can find a suitable replacement. Other interesting Web Debugger alternatives to Fiddler are HTTP Toolkit, Charles, Zed Attack Proxy (ZAP) and Requestly.
mitmproxy is an SSL-capable man-in-the-middle proxy for HTTP. It provides a console interface that allows traffic flows to be inspected and edited on the fly. It also features mitmdump, a commandline tool that provides a tcpdump-like interface for saving, viewing and...
HTTP Toolkit is a beautiful, cross-platform & open-source HTTP(S) debugging proxy, analyzer & client, with built-in support for modern tools and automatic interception for clients from Docker to Android to iOS.
Spain
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Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).
New Zealand
The Zed Attack Proxy (ZAP) is an easy to use integrated penetration testing tool for finding vulnerabilities in web applications.
Requestly is a lightweight proxy available as a browser extension & desktop app to intercept & modify network requests. Using Requestly you can Modify Headers, Redirect Url, Mock API response, Delay/Throttle requests, etc.
United States
HTTP Debugger captures and decrypts HTTP/HTTPS from any Windows app without proxy setup — HTTP/2, WebSocket, SSE, gRPC and localhost included. Edit and replay requests, modify traffic on the fly, and let an AI assistant read the session over the built-in MCP server.
Network Spy is a cross-platform network proxy and traffic analyzer built with Tauri, Rust, and React. It helps developers intercept, inspect, decrypt, and debug HTTP(S) traffic through a fast and modern desktop interface.
Indonesia
Working quietly on the Menubar, Surge is a high-performance HTTP/SOCKS5 proxy server. It is capable of intercepting and logging the summary of HTTP traffic, and meanwhile transmitting the traffic to other proxy servers according to the flexible rule system.
HttpFox monitors and analyzes all incoming and outgoing HTTP traffic between the browser and the web servers.
GermanyEU
James is a HTTP Proxy and Monitor that enables developers to view and intercept requests made from the browser. It is an open-source alternative to the popular developer tool Charles.
Fluxzy Desktop is an HTTP and HTTPS debugging proxy for Windows, macOS, and Linux. If you already use Fiddler, Charles, or Proxyman, you know the drill: capture traffic, inspect requests and responses, tweak them, replay them. Fluxzy does all of that, with support for HTTP/1.
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