Web Debuggers

Fiddler is a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP(S) traffic, set breakpoints, and "fiddle" with incoming or outgoing data.

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...

The Google Chrome Developer Tools provide an integrated environment for debugging, optimizing, and understanding a web application, or website, running in Google Chrome. The developer tools are developed partly through the WebKit open source project, where the tools are called...

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).

Examine, edit, and debug HTML, CSS, and JavaScript on the desktop and on mobile.

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.

HTTP Debugger Pro - A Professional HTTP Sniffer and Analyzer for Developers.

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.

The goal of this project is to adds information about the HTTP headers in three ways:

HttpFox monitors and analyzes all incoming and outgoing HTTP traffic between the browser and the web servers.

Live HTTP Headers logs all HTTP traffic between Google Chrome and the Internet.

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.

Cross platform Web debugging proxy.

Proxy.app is the perfect tool for debugging and analysing both HTTP requests and responses and modify data in transit. It can be used to debug hard problems while doing web development or as a penetration testing tool during security assessments.

HTTP Headers allows you to quickly see the HTTP header information for the current URL.