APIs are the basis of modern software development, especially as more and more teams move away from monolithic applications and begin adopting a microservices approach to software development.
With microservices making up the backbone of most newer development efforts, API testing becomes even more critical than before.
The following are the top API testing tools that can help you on your journey, with descriptions that should guide you in choosing the best fit for your needs.
REST-Assured
When using Java, REST-Assured is my first choice for API automation. In fact, it’s the main tool I use for API testing.
REST-Assured is a fluent Java library you can use to test HTTP-based REST services. It’s designed with testing in mind, and it integrates with any existing Java-based automation framework. The REST-Assured API was created so that you don’t necessarily need to be an HTTP expert.
Postman
Some folks don’t want to code in an integrated development environment using the same language as the developers. After all, if your developers don’t contribute to your automation efforts, why force yourself to use their tech stack when it’s not the best option for you?
Postwoman
Postwoman, an alternative to Postman, is a new tool that has gained in popularity over the past few months. It has a clean and modern UI that makes creating API requests fast and easy.
JMeter
Although JMeter was created for load testing, many folks also use it for functional API testing.
JMeter includes all the functionality you need to test an API, plus extra features that can enhance your API testing efforts. For example, JMeter can automatically work with CSV files, so your teams can quickly produce unique parameter values for your API tests. It also integrates with Jenkins, so you can include your API tests in your CI pipelines.
Fiddler
Fiddler lets you monitor, manipulate, and reuse HTTP requests. It does many things that allow you to debug website issues, and, with one of its many extensions, you can accomplish even more.
Citrus Framework
The Citrus Framework can help you automate integration tests for virtually any messaging protocol or data format.
Insomnia
After looking at Insomnia, I’m not sure how I ever missed it. It’s free and easy to use, and it has a beautiful interface. Some other benefits of Insomnia are that it allows you to:
- Create HTTP requests
- View response details
- Organize your tests
- Reuse values
- Generate code snippets
PowerShell
PowerShell is an open-source Microsoft product. So pretty much anytime you want to use the command line or automate anything, such as API tests inside the Windows ecosystem (or pretty much any Microsoft product), you should go with PowerShell.
Taurus
Taurus is an automation-friendly framework for continuous testing. Because you can use it with JMeter, it can handle API testing.
Taurus is great to use when teams want to take a more BDD-based testing approach to their API testing efforts. Using YAML files gives you clear, easy-to-read tests that anyone on your team can understand.
Time to choose
There is no one perfect tool for everyone: Every organization has different requirements. Virtually all of the API test tools listed above work well and are great options. The key is to read through the descriptions carefully and decide which best fits your team’s needs.
