Open Source JavaScript Debuggers

James is an 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. James is built with hoxy, electron and react. Use wildcards in the "url to map" field, put a "*" between two adjacent slashes. The electron instance will automatically reload whenever a change is made. Download the correct version for your OS.

Most Popular developer tool for frontend developers & QAs to debug web and mobile applications. Redirect URL (Switch Environments), Modify Headers, Mock APIs, Modify Response, Insert Scripts & Report Bugs with debugging sessions. Bring the power of Charles Proxy, Fiddler & Postman together with beautiful, modern UI & collaboration features. Available as a browser extension on all major browsers & desktop apps on all platforms. Requestly is an Open-Source platform for front-end developers with essential tooling & integrations that helps them write, test & debug their code 10x faster. Requestly reduces dependency on backend devs and environments for development & testing needs. Using Requestly, devs can create mock, test, validate & override API responses, modify request & response headers, set up redirects (Map local, Map remote), and use Requestly sessions for faster debugging.

This package improves child_process methods with a promise interface. Strips the final newline from the output so you don't have to do stdout.trim(). Supports shebang binaries cross-platform. Improved Windows support. Higher max buffer. 100 MB instead of 200 KB. Executes locally installed binaries by name. Cleans up spawned processes when the parent process dies. Get interleaved output from stdout and stderr similar to what is printed on the terminal. (Async only). Can specify file and arguments as a single string without a shell. More descriptive errors. Gracefully handle failures by using automatic retries and exponential backoff with the p-retry package.

kodeWeave is a realtime coding playground for HTML, CSS and Javascript. Similar to JSFiddle and JSBin, but kodeWeave was made to work offline but also as a prototyping application to build applications for desktop operating systems while on mobile devices. (PhoneGap Build is recommended for mobile devices) kodeWeave similar to jsfiddle, jsbin, dabblet, liveweave, codepen, cssdeck, cssdesk, tinkerbin, d3 playground, plunker and pastebin, but allows you to export your web app as a desktop and/or chrome application.

A C#, C++, Delphi, ActiveX ,javascript and Java trace framework and a trace viewer: Tail, outputDebugString, event log, Log4J, Log4Net, Microsoft EIF support and Pocket PC development (C++ and .NET)

JSGB is a Nintendo GameBoy emulator. Written in JavaScript and HTML5. Integrates a debugger with breakpoints support, memory, viewer and more... You can test it here: www.codebase.es/jsgb/?v=0.02

This is a console that has been made in JavaScript that allows user to log there information including general info, warn, errors etc. The user can also add watch on variables.

This debugger for PHP gives you the ability to inspect and understand what is going on in your application.

javascript logger based on Prototype 1.4

Betwixt will help you analyze web traffic outside the browser using familiar Chrome DevTools interface. Download the latest release for your operating system, build your own bundle or run Betwixt from the source code. In order to capture traffic, you'll have to direct it to the proxy created by Betwixt in the background.

Z80 ASM editor that gives you real-time info about Mnemonics, Waitstates/Clock cycles, and Labels. Features code completion, real-time debugging and T-states profiling.

CMakeScript is an extension to CMake, a cross-platform, open-source build system. CMakeScript adds Java Script as alternative script language to CMake's home-grown macro language. CMakeScript comes with a visual debugger for Java Script.

CodeInvestigator is a tracing tool for Python programs. All the run time information is recorded. Read your code together with its run time details. Use it to visualize what happened when you program ran.

ConSense is a singular "jack of all trades" web development console intended to ease all your bugtracking, testing and page architecture tasks. Its siblings, RedSand and SimpleClasses form a sound, dynamic, object oriented JavaScript/DHTML framework.

ElementProps is an Internet Explorer context menu extension that displays the properties of any DOM node in the current web page, including dynamically created elements and attributes.

ESA Provides a wrapper around the .NET scripting engine which adds support for hosting the scripting engine in a seperate AppDomain, and includes a Design-time environment for applications.

Fireclipse: experiments in leveraging Eclipse + Firefox for Javascript Development

GDBFrontend is an easy, flexible and extensionable GUI debugger. Try it online! GDBFrontend has an expression evaluator that you can use multiple at the same time. Right-click to a breakpoint for setting its condition. Expressions of all variables, members, and items are connected in GDBFrontend's VariablesExplorer. You can watch, filter or manage processes with Process Manager. GDBFrontend has a set of features for collabration named as "Enhanced Collabration". Collabration draw is available when you enable Enhanced Collabration. Click to Draw or use Ctrl + Shift + X shortcut to draw and Ctrl + Shift + C to clear all drawings. With Enhanced Collabration all debugger clients are synchronized on source viewing. GDBFrontend is very extensible and has powerful APIs. Some examples of GDBFrontend's extensibility.

Goldpinger makes calls between its instances to monitor your networking. It runs as a DaemonSet on Kubernetes and produces Prometheus metrics that can be scraped, visualized, and alerted on.

When I got my first Android tablet; I realized how much web design and development were such a tedious process for a large majority of tablet and smart phone users. I found no applications available in Google Play that enabled live code debugging which gave me the incentive to develop one myself. After purchasing Google's developer fee, as well as AIDE I then released on Google Play for all to use.

This Library allows you to perform unit testing in Javascript, to practice TDD and to produce the most fun Game of Life for a code retreat or coding dojo! :D You can watch is alive here: http://js-tdd.sourceforge.net/

The project is designed to make life easier for programmers using javascript. Updated trace panel(disegner will work on it later :) ). And one issue with IE6. Compatible with IE7+, Chrome, FF2+, Opera(?)

Jackal JavaScript Debugger is a debug tool written in javascript for client-side javascript debugging.It supports runtime access to the loaded script. Allows editing functions, variables etc at runtime. Beta version 3.0.0 released

Jdptool is a debug and profiler tool which based on JPDA; It provide both swing based and browser based GUI. It has sophisticated debugger without user interfere. It also provide profiler to memory usage and threads with numerous new feature

A cross-browser Document Object Model inspector based upon the successful DOM Inspector provided with Firefox.