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Hello guys, If you are a Java or web developer working on REST APIs and RESTful web services and looking for some tools to test your APIs and web services then you have come to the right place.

Earlier, I have shared the best books and courses for RESTful web services and in this article, I am going to share seven awesome but easily accessible and free tools to design, development, test your REST APIs.

These REST API tools will help you to design, development, and test your APIs as you build, starting from unit testing to integration testing and then fully automating your resting to create a regression pack.

You can also use these tools to interact with your REST API during the development phase for quick tests.

Some of you might already familiar with these tools, commands, and library in that case just chip in and share your experience so that we can all learn from each other.

If you ask me, I generally used the curl command for simple testing like to see what data a particular REST endpoint return but for more sophisticated testing I generally use tools like Postman, RESTAssured, or SOAPUI.

Anyway, without any further ado, here are some tools you can use to test your REST APIs or RESTful web services, as we Java developer calls them. I will also add more tools and their examples as and when I find them, but for now I have shared the tools and resources for further learning them.

By the way, If you are a beginner and want to learn RESTful web services in Java and looking for some recommendations then I highly recommend you to join the Master Java Web Services and RESTful API with Spring Boot course on Udemy. This is also the most affordable course to learn REST API with spring boot.

7 Best REST API Tools for Developers in 2023

Without wasting any more of your time, here is my list of best tools for REST API testing for Java developers. You can use these tools to interact with your RESTful web services like sent HTTP GET and POST requests, monitor response code, examine headers and cookies and inspect data.

1. Swagger

Swagger is another great tool for REST API development that you can use to document and share your REST API specification. Swagger provides a standard format to describe REST APIs.

By following those rules you can create REST API documents to share among product managers, testers, and developers, but can also be used by various tools to automate API-related processes

It's also known as Open API Specification and it's currently the most popular way to create definitions of RESTful APIs. With these definitions, you can create sophisticated, autogenerated documentation, generate SDKs in several languages, and do automated testing

If you want to learn more about Swagger and how to use it in a real-world project then I highly recommend you to check out Learn Swagger and the Open API Specification course by Peter Gruenbaum on Udemy. It's a great resource to learn Swagger in 2023.

2. PostMan [Best manual and Automation testing]

If you are not a big fan of command-line tools and rather like a GUI client to test your REST API then Postman is the best tool for you. It comes as a Chrome extension and you can install it on your chrome browser and from thereon.

It probably the most popular tool to test your REST API. If you look at their website, you will find that Postman is used by 5 million developers and more than 100,000 companies to access 130 million APIs every month.

It's also feature-rich and supports every stage of the REST API lifecycle. Through design, testing, and full production, Postman is there for faster, easier API development---without the chaos.

Doesn't matter whether you are working in Windows, Mac OS, or Linux, you can download the Postman app to test your REST APIs anywhere. If you want to learn more about Postman tools for REST API Testing, I highly recommend you join Postman: The Complete Guide - REST API Testing course by Valentine Despa on Udemy. It's a great resource to effectively use the Postman tool.

3. RESTAssured [Best for Automation Testing]

As a Java developer, this is my preferred way to test REST APIs automatically. If I not doing any manual testing using curl or Postman then I use REST Assured to write tests in Java for our REST APIs.

It's like JUnit for REST APIs but much better.

If you have worked in dynamic languages like Ruby, PHP, and Python then you know that writing something in Java involves a lot of ceremonies but RESTAssured handles that for you and it allows you to write test in a clear, descriptive language like when you call this rest service you expect this response code, this data, etc.

I strongly recommend to Java developer and automation tester to learn RESTAssured for automation testing and if you need resources then Rest API Testing (Automation) from Scratch -RestAssured Java course by Rahul Shetty on Udemy is a good place to start with.

5. Curl

This is my favorite tool and almost 50% of the time I use this. The main reason for that is because I love Linux commands. The curl or cURL command allows you to send different types of HTTP requests e.g. GET, POST, PUT, and DELETE which you can use to test basic functionalities of your REST APIs as shown in my earlier article about testing REST APIs using the curl command in Linux.

It also allows you to set HTTP headers which means you can set Content-Type or Accept header to test content negotiation like I often set Content-Type="application/json" to get a JSON response from the REST API.

If you don't use curl command yet then you are missing out big time, not just REST APIs the tool allows you to send any application which is dependent upon HTTP.

I have used curl in the past to write health check scripts that pings our web service, wait for some time, and report if it doesn't receive any response. In general, knowing Linux command helps a lot and if you want to learn them, then the Linux for Beginners course by Bogdan Staschuk on Udemy is a good place to start with.

5. SoapUI

SoapUI is the world's most widely-used automated testing tool for SOAP and REST APIs. You can use SoapUI to write, run, integrate, and automate advanced API Tests easily in your project.

Many developers use SoapUI to test APIs, both during design and development and after deployment for support.

The best thing about SoapUI is that you can use this tool to test both SOAP Web Services as well RESTful Web Services or HTTP-based services.

SoapUI also supports all the standard protocols and technologies which means you can use it to test all kinds of APIs. Its design and interface are also very simple that enables both technical and non-technical users to use them seamlessly.

If you want to learn how to use SoapUI to test real-world projects then I highly recommend you to join Rahul Shetty's Web Services/Rest API Testing with SoapUI +Real time Projects course on Udemy.

More than 60K API developers and testers have already joined this course and it's quite hands-on. You will see as well as learn along the way how to test real-world REST APIs using SoapUI.

6. Resty

This is another command-line tool to test your REST APIs. It's nothing but a small script wrapper around curl that focuses on testing REST APIs. Just install this little tool and source and you can start testing your REST APIs from the command line.

It is implemented as functions in your shell which means you can combine Resty with other powerful shell tools, such as Perl, awk, grep, sed, etc.

You can use resty in pipelines to process data from REST services, and PUT, PATCH, or POST the data right back. You can even pipe the data in and then edit it interactively in your text editor prior to PUT, PATCH, or POST.

7. HTTPie

Httpie is another command-line tool that you can use to test your REST APIs. It's nothing but an HTTP client with an intuitive UI, JSON support, syntax highlighting, wget-like downloads, plugins, which makes testing REST APIs easier and fun.

HTTPie consists of a single http command designed for painless debugging and interaction with HTTP servers, RESTful APIs, and web services, the built-in JSON support makes sending JSON requests like in POST and PUT command easier while testing REST APIs.

That's all about the best tools to design, development, document, and test your REST APIs and RESTful Web services. As a Java developer, I recommend you to write your test in code using RESTAssured but if you want interactive testing, curl is your best friend, particularly if you are in Linux. If you are a Windows-based GUI lover developer then Postman is your best friend.

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Thanks for reading this article so far. If you find these REST API testing tools for Java developers then please share them with your friends and colleagues. If you have any questions or feedback, please drop a note.

P. S. - If you are a beginner and want to learn RESTful web services in Java and looking for some recommendations then I highly recommend you to join the Master Java Web Services and RESTful API with Spring Boot course by Ranga Karnam of In28Minutes on Udemy. This is the best course to learn REST APIs for Java developers.

7 API Tools for REST Developers and Testers