The best HTTP(S) 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 13 are HTTP(S) Debuggers so hopefully you can find a suitable replacement. Other interesting HTTP(S) Debugger alternatives to Fiddler are HTTP Toolkit, Charles, Proxyman 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
Monitor, intercept and debug HTTP/HTTPS and WebSocket traffic on macOS, iOS, Windows, and Linux. Includes advanced features such as Breakpoint, Map Local/Remote, scripting, filtering, reverse proxy, DNS spoofing, and automation for backend development.
United States
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.
Caido is a cutting-edge web application security tool that enables users to efficiently identify and assess potential vulnerabilities in their web applications. It can be easily integrated into both personal and enterprise environments, making it adaptable to a wide range of...
United States
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
SmartSniff is a packet sniffer that capture TCP/IP packets and display them as sequence of conversations between clients and servers. You can view the TCP/IP conversations in Ascii mode (for text-based protocols, like HTTP, SMTP, POP3 and FTP) or as hex dump (for non-text base...
Israel
Open-source native macOS HTTP debugging proxy — intercept HTTPS, inspect APIs, mock responses, debug WebSocket & GraphQL. Community-driven. For developers, by developers.
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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