6 Great API Testing Tools You Should Use in 2018

APIs have always been a vital part when it comes to software development and how the software serves its purpose. Web-based applications are too common now, and are heavily relied on by organizations and individuals alike. This makes proper API testing more crucial than ever.

In this post, we will be sharing 6 great API testing tools that would come in handy for software testing efforts this year.

1. Soap UI

Soap UI is a popular open source testing tool used primarily for web services testing and API testing. Its functionality is useful for invoking, development, simulation, web service checks, load testing, functional testing etc. to name a few.

2. Frisby.js

An open source JavaScript library, Frisby is built on NodeJS and Jasmine (a Behavior-driven development style test runner). The community considers it a great REST API testing framework facilitating simpler and faster testing of API endpoints.

Frisby.js 2.0 is coming out soon with further improvements making the underlying Jasmine structure more extensible and exposed. The Jasmine node test runner makes it possible to run Frisby tests in a continuous integration ecosystem.

3. Karate DSL

Karate DSL is an open source command-line testing framework that uses BDD to define API tests. The framework is more familiar to people who use Cucumber JVM for BDD tests, as it’s built on Cucumber JVM. Like Frisby, Karate DSL also supports seamless integration and continuous delivery pipelines.

It also supports testing live environments, in addition to providing comprehensive support for common HTTP calls that use HTTPS, HTTP proxies, SOAP/XML etc.

4. Postman

Unlike its other counterparts mentioned above, Postman is a hosted GUI API Testing client used for exploratory testing primarily. It features documentation, sharing, and monitoring support in addition. Its broad set of features make it a very useful API testing tool.

Another advantage is that Postman runs on local machine, giving control of data. However, not all software testing companies prefer using Postman, and it’s not because of a lack of features. Many companies would have security restrictions due to which they won’t be able to use a fully hosted option. Like most other tools in this list, Postman also supports testing in a continuous integration pipeline.

5. Assertible

Assertible is more popular and preferred compared to Postman as it focusses more on automation and reliability. The tool also features HTTP response validation with turnkey assertions.

Its greatest advantage is the fact that it allows automation of API tests through every step of a continuous integration/delivery pipeline, making things much easier for smaller groups of testers.  It can integrate with tools like GitHub, Slack, and Zapier, and supports running API tests post deployment.

6. Apigee API Studio

Testers can use the API Studio from Apigee to build APIs. The Studio also facilitates easier and effective API testing thanks to its many features designed specifically to simplify testing. One of the major use cases is for API Response Simulation with mock HTTP responses. However, it is still in its beta but the community expects many updates this year which will add more features to the already useful tool.


There are a great number of useful tools for thorough API testing, but the ones listed above are quite unique. Most of them are still rising among the ranks but handy nonetheless. This list should be helpful for testers who would like to explore tools that can make their work easy. It’s a new year, and introducing yourself to new testing tools might be the change you are looking for. Try them out.