1. CLI HTTP that will make you smile. JSON support, syntax highlighting, wget-like downloads, extensions, and more.

  2. Beautiful, cross-platform & open-source tools to debug, test & build with HTTP(S). One-click setup for browsers, servers, CLI tools, scripts and more.

    freemium €6.0 / Monthly (for a Pro subscription)

  3. Fiddler is a debugging program for websites.

  4. Postman is the most efficient way to test, develop and document APIs.

    freemium $8.0 / Monthly (Per user/month billed annually)

  5. The most intuitive cross-platform REST API Client 😴

  6. cURL is a computer software project providing a library and command-line tool for transferring data...

  7. SoapUI Pro is one of the most prominent API testing platforms around, allowing developers to quickly prototype the functions of their apps and get them to market with little hassle.

  8. Paw is a REST client for Mac.

  9. HTTP proxy / HTTP monitor / Reverse Proxy

  10. RESTClient can be used to test variety of HTTP communications and RESTful webservices.

  11. StopLight, providing engineering teams with the best way to document, test, and build web APIs.

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