Insomnia REST Client!

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.

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.

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.

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

Powerful, modern HTTP / REST client for Sublime Text. Requester has an expansive feature set, modern UX, powerful, elegant syntax and first class support for API testing and test automation. It runs on macOS, Windows and Linux. Some features:

Assertible is the easiest way for teams and individuals to test and monitor web services. Gain confidence in crucial infrastructure by using Assertible's automated QA tools to test and monitor your web services across deployments and environments. With modern and easy-to-use assertions, you can validate virtually any web service, run your tests on any environment, and integrate with your CI or deployment pipeline. Save time and get your job done faster by automating your QA with Assertible.

RESTtest is a simple yet intuitive way to test RESTful web services and standard HTTP calls. RESTtest allows you to enter a HTTP request body and any necessary headers. After the request is submitted, response information can be both viewed and saved to disk.

FRequest is a fast, lightweight and opensource Windows / MacOS desktop program to make HTTP(s) requests (e.g. call REST apis).