Top 10 API Testing tools ( for 2020 )

API (Application Programming Interface) Testing is a type of testing that validates if the APIs are developed as per the requirements.

TOP 10 API Testing Tools
Top 10 API Testing Tools - 2020 -

The APIs can be tested for functionality, reliability, performance security etc. Since APIs have become core of software development, it's very important to test them. And to support testing of APIs there are so many tools available in the market. Here is the list of tools that you can use to test your APIs


Started as a chrome plugin, now Postman is available as native Windows/OS X application. Postman is a complete API development environment. As of writing this post, there are 10 million developers, half a million companies using Postman. This shows how popular postman is.
Postman - Top API testing tools - RightQA


  • Easy to author tests
  • Simple yet powerful user interface for writing tests
  • Can be used to do exploratory API testing, as well as automated API testing
  • Ability to write custom scripts to help testing (in JavaScript)
  • Environment variables to test same API in different test environments
  • Easy to add assertions

Katalon Studio

Katalon Studio is a 2020 Customers' Choice in Software Test Automation. Katalon Studio is a free test automation tool for Web, Mobile and Desktop applications, and API/Web Services.
Katalon Sudio - Top API testing tools - RightQA


  • Supports both RESTful & SOAP services
  • Supports data-driven testing
  • You can add a combination of UI and API verification
  • Can be picked up by both, techies and non-techies


Postwoman is a free, fast and beautiful API request builder. It is a web alternative to Postman (nothing to install, just open up the browser and start using). It is gaining popularity recently. As of March 2020, it has 18K stars on github, indicating that folks are finding it useful (github star count is not necessarily an indicator of repo being good or anything, it's just my personal interpretation).
Postwoman - Top API testing tools - RightQA


  • No installation required, everything runs in a browser!
  • Highly customizable
  • Supports GraphQL
  • You can create collections and re-use them


Insomnia is a powerful HTTP & GraphQL tool belt. It's FREE and open source for MAC, Linux and Windows

Insomnia - Top API testing tools - RightQA


  • Create HTTP requests
  • View detailed response (view status code, response body, headers, cookies and more!)
  • Organize tests easily
  • Much more than an HTTP client
  • Advance authentication helpers, templating and request chaining will help you get things done faster
  • Reusable values (environment and global variables)
  • Code snippet generation


SoapUI is an API testing tool, allowing users to test REST and SOAP APIs as well as Web Services easily. SOAPUI comes in 2 version, FREE and PRO

Free version: allows users to create tests quickly and easily with Drag and drop, Point-and-click

Pro version: allows users to create powerful data-driven tests by allowing the data to be loaded from files, databases and Excel.
Support native CI/CD integrations, asynchronous testing
SOAPUI - Top API testing tools - RightQA


  • SOAP API Testing
  • REST API Testing
  • WSDL Coverage
  • Scripted Assertions

Karate DSL

Karate is an open-source tool to combine API test-automation, mocks, performance-testing and even UI automation into a single, unified framework. The BDD syntax popularized by Cucumber is language-neutral, and easy for even non-programmers. Powerful JSON & XML assertions are built-in, and you can run tests in parallel for speed.
Karate - Top API testing tools - RightQA


  • Java knowledge is not required and even non-programmers can write tests
  • Scripts are plain-text, require no compilation step or IDE
  • Based on the popular Cucumber / Gherkin standard - with IDE support and syntax-coloring options
  • Elegant DSL syntax 'natively' supports JSON and XML - including JsonPath and XPath expressions


Using Swagger, you can start your functional, security, and performance testing right from the OpenAPI Spec. Swagger tooling and the ReadyAPI platform make it easy to rapidly create, manage, & execute API tests in your pipeline.

Swagger - Top API testing tools - RightQA


  • Swagger simplifies testing across your APIs - REST, SOAP, or GraphQL. 
  • Swagger Inspector puts no limits to how you test, explore or generate your definitions from any form or type of API.
  • Swagger Inspector provides capabilities to inspect API request-responses, and make sure they perform as expected


JMeter is mostly widely used as a performance testing tool, but many teams/developers/QAs use them for functional API testing as well. 
JMeter - Top API testing tools - RightQA


  • Tests can be easily integrated in CI due to nice integration between JMeter and Jenkins
  • Same tests can be used for functional and performance tests
  • Allows you to record your HTTP requests (tests) and replay them
  • Since JMeter is an established tool, there are so many plugins that you can find to support your testing

REST Assured

REST-Assured is a Java DSL for easy testing of 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 a pro to start using it.
REST-assured - Top API testing tools - RightQA


  • DSL-like syntax
  • XPath-Validation
  • Specification Reuse
  • Easy file uploads
Now , there are so many other tools out there in market for API testing. But you have to pick the one that fits your needs. Not all tools will be useful in all conditions.

Please comment which tool do you use for your API testing.