Windows RestClient!

Firebug integrates with Firefox to put a wealth of web development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page.

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. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.

cURL is a computer software project providing a library and command-line tool for transferring data using various protocols with URL syntax: supporting FTP, FTPS, SCP, SFTP, HTTP, HTTPS, TFTP, TELNET, DICT, LDAP, LDAPS and FILE. cUrl supports HTTPS certificates, HTTP POST, HTTP PUT, FTP uploading, kerberos, HTTP form based upload, proxies, cookies, user+password authentication, file transfer resume, http proxy tunneling and a busload of other useful tricks.

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 Web Inspector.

Postman helps you be more efficient while working with APIs. Postman is a scratch-your-own-itch project. The need for it arose while one of the developers was creating an API for his project. After looking around for a number of tools, nothing felt just right. The primary features added initially were a history of sent requests and collections. A number of other features have been added since then. Here is a small list.

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

Eviware, the maker of soapUI, Web Service Testing Leader

The web developers helper program to create and test custom HTTP requests.Advanced REST client for Google Chrome.

Debug APIs like a human, not a robot.

Runscope helps you monitor, log and measure API usage to solve API problems fast. Automatically monitor APIs without any coding. Runscope provides complete logging for all of your API traffic. Track down troublesome API calls with powerful search. Debug problems by peering into the details of every request and response. Works with any public or private API, behind the firewall or in the cloud.

NetworkMiner is a Network Forensic Analysis Tool (NFAT) for Windows. NetworkMiner can be used as a passive network sniffer/packet capturing tool in order to detect operating systems, sessions, hostnames, open ports etc. without putting any traffic on the network. NetworkMiner can also parse PCAP files for off-line analysis and to regenerate/reassemble transmitted files and certificates from PCAP files.

A REST client for almost any web service (Firefox and Chrome extension).