Top Tools / September 6, 2021
StartupStash Team

The world's biggest online directory of resources and tools for startups and the most upvoted product on ProductHunt History.

Top 26 API Testing Tools in 2021

Before we begin with the top 26 API testing tools in 2021, let’s start with the basics of API testing tools.

With Application Programming Interface becoming an important component for software development, it has become essential to perform API tests. API testing focuses on ascertaining if the API that has been developed passes the threshold of performance, functioning, security, and reliability.

Since API tests have become important, you need to find the top tools for API testing. With hundreds of API tools to choose from, you must probably be wondering, which is the best API testing tool?

We have curated a list of the best API testing tools in 2021 that will make your work easier and faster.

1. Katalon

Katalon is one of the best API load testing tools that provide a hassle-free platform to perform API tests without any prior experience of programming. This tool can be used on the web, desktop, and mobile phones.

Katalon is turning out to be one of the best API testing tools 2021 because of its simple user interface and easy-to-use API services for developers as well as testers.

Key Features:

  • Supports REST, the SSL client certificates, and SOAP requests

  • You can set up API test data with UI testing

  • You can import your tests from Swagger, WSDL, Postman, and, WADL easily

  • It supports AsserJ so that you can make a fluent assertion in BDD style

  • Provides better test reliability and test coverage

  • Better collaboration across teams because of its insightful test report dashboards

Cost:

Free for small teams, advanced version starts at $76/month

2. Test Mace

Test Mace is one of the best performance testing tools for API that creates automated API tests. It helps in creating and testing complex scenarios very fast without actual programming.

It has a well-organized project structure that allows you to save your project in the version control system.

Key Features:

  • It has an autocomplete feature

  • Allows Cloud synchronization

  • You can highlight the current variable values

  • Has advanced JS support in the code editor

  • You can evaluate expressions in every text field

  • Supports CI/CD

Cost:

Basic Version is free, Individual is for $4/month, and Team price is $8/month

3. Parasoft SOAtest

Parasoft SOAtest is one of the best API tools for testing that can perform automated tests as a part of CI. It creates codeless API tests using manual recordings to automate testing complex systems. SOAtest can efficiently transform your test artifacts into security tests.

Key Features:

  • Increased reusability

  • Smoothly integrates with service virtualization and load testing

  • It can generate codeless API tests automatically

  • It can leverage artificial intelligence that creates powerful test scenarios in comparatively less time than most API tools

Cost:

Free

4. RapidAPI Testing

RapidAPI Testing has more than 1 million developers and 10,000 APIs. It is one of the best API security testing tools that provide a functional solution to create and manage comprehensive API tests. You can run any type of API using this tool including SOAP and REST.

Key Features:

  • Offers global monitoring

  • Unlimited tests

  • Can create comprehensive tests for API validation

  • You can run tests continuously to monitor APIs all over the world

  • CI/CD integrated

  • Sends real-time alerts

Cost:

Free testing for first 10,000 APIs

5. Soap UI

Soap UI has become widely popular and is one of the best API testing tools 2021. It allows you to test SOAP and REST APIs easily because it has been specifically built to test APIs. The quick and easy test creation makes it simple to work with complicated tasks.

Key Features:

  • You can load data from files and databases to test and understand the way your customers interact with your API

  • Reusable scripts

  • Integrated with 13 API platforms

  • Supports SOAP, REST, and JMS

Cost:

14-day free trial, packages start from $749/license

6. Postman

Postman is a Google Chrome plugin that is used for API testing services. It is one of the best web API testing tools to test web services. If you are looking for manual or exploratory testing, then Postman is the best choice for your API testing.

Key Features:

  • You can extract almost all modern web API data using Postman

  • Easily write Boolean tests

  • Create a collection of REST calls

  • You can save calls to execute them in the future

  • No hassle of pasting text into the command line

  • Reliable for transmitting and receiving REST information.

Cost:

Free, For teams $12

7. Rest-Assured

Rest-Assured is one of the best API testing tools open source that makes testing REST APIs simpler. It comes with a library of baked-in functionalities so that its users don’t have to create code from scratch.

Key Features:

  • Integrated with Serenity automation framework to allow users to consolidate UI and REST tests in a single space

  • Supports Apache Johnzon

  • Supports BDD syntax

  • User-friendly interface

Cost:

Free, $4 for Teams

8. Tricentis

Tricentis is a web service testing tool that supports a wide range of protocols like HTTP, AMQP, SOAP, JMS, etc. It is one of the best API testing tools with easy script maintenance.

Key Features:

  • Integrated with Agile and DevOps Cycle

  • Uses model-based automation

  • Easy to maintain scripts

  • Allows end-to-end testing

Cost:

$1,000 for license

9. JMeter

JMeter was originally created for load testing, but it is one of the best API testing tools in the market now. You can find a number of API testing functionalities in JMeter and other features as well that make the API testing more efficient.

Key Features:

  • You can add API tests in the CI pipelines because of their integration with Jenkins

  • Replay test results

  • Can be used in dynamic and static performance testing

Cost:

One month free trial

10. API Fortress

API Fortress helps you test REST and SOAP APIs with its powerful monitoring and testing tool. It is known for its simple user interface which has made many companies switch to API fortress for API testing.

Key Features:

  • You can easily generate a test with one click

  • It is compatible with Cloud

  • User-friendly interface for beginners

  • Gives real-time updates

Cost:

Starts from $15000 per year

11. Karate DSL

Karate DSL is a fairly new API tool. It helps create API-based BDD tests simply without having to write the step definitions. The step definitions have already been created by Karate so that its users can jump to API testing promptly.

Key Features:

  • You can create reports just like in Java projects

  • Supports multithreaded parallel execution

  • Easy to write tests

  • Allows you to switch/stage

  • You don’t need Java knowledge to work on this tool

Cost:

Free

12. HttpMaster

HttpMaster is one of the best tools to automate API testing. It is a web development tool that enables web application testing, service testing, and API testing. It is primarily used for Web API tests.

Key Features:

  • You can use any HTTP method like POST, GET, DELETE, etc.

  • Various data types have different dynamic parameters to create different API requests

  • Several validation types

Cost:

30-day free trial, License starts at $99

13. vREST

vREST is one of the best tools for API security testing that offers an online solution for API automated testing, recording, and mocking. With this tool, you can quickly validate your REST API using its exhaustive tool.

Key Features:

  • Delivers zero-defect applications with minimum effort in API testing

  • You don’t require programming skills to validate your web application through this tool

  • Can generate documentation for API if required

  • You can create API mocks using the Mock Server Functionality

  • You can start developing a frontend with the mock HTTP requests directly

Cost:

Free, Enterprise starts at $10 per month

14. PAW

Paw is a one-stop robust tool used for testing and describing API on Mac. It is loaded with various features that help you build HTTP requests. You can also generate code with this API tool.

Key Features:

  • Offers multiple features

  • Has Teams Product

  • Has multiple extensions

  • Allows you to organize requests by host or name

Cost:

$49.99 for a one-time license, $10 per month for teams

15. Airborne

Airborne is one of the best programming and API automation tools that is used to test a REST API. Since it is a programming tool, it does not have an interface except the text file that is used to create code.

Key Features:

  • It is a REST API testing framework without a user interface

  • It is easy to use

  • Just with a few key methods, you can quickly test your API

Cost:

Free

16. Ping API

Ping API allows you to write scripts using JavaScript or CoffeeScript and test your API. It is one of the best testing tools for API that allows investigating HTTP API calls with entire response data. In case of a failure, the user gets notified via Email or Slack.

Key Features:

  • It can schedule tests every minute

  • You can set request headers, body, and URL because it supports script writing

  • Validates CRUD flow

Cost:

The first project is free, next project starts from $5 per month

17. Apigee

Apigee is another one of the best API testing tools of 2021. It offers cross-cloud API testing tools that allow you to test the performance of your API. You can also create an API with the help of excellent editors like Swagger.

Key Features:

  • You can monitor, scale, design, and deploy APIs all in one

  • Supports Node.js

  • You can identify performance-related problems by tracking the error rates of your API

  • Customizable developer portal

Cost:

Contact the site

18. Soapsonar

SOAPSonar is one of the best API testing platforms that provide web-based services. You can use external sources like Oracle, Excel, SQL, etc to automate tests.

Key Features:

  • Identifies web services

  • Offers web service functional testing with concurrent client load testing

  • Integrated with Ant, JUnit, and, Hudson

Cost:

Free

19. REST Console

REST console is an HTTP client that constructs REST API testing. It helps developers build and dubbed APIs before putting them to test.

Key Features:

  • You can construct put or post body using raw input

  • You can add custom headers using the intuitive user interface

  • Shortcuts available

  • The query parameters creation is easy

Cost:

Free

20. Pyresttest

Pyresttest is an API testing tool that is Python-based. You can test files that are JSON or YAML configured with this tool. You don’t need code to use this tool.

Key Features:

  • Allows easy deployment because of its minimal dependencies

  • The exit codes will return in case of API test failure

  • You can extract mechanisms to build test scenarios

Cost:

Open Source

21. Hippie-Swagger

Hippie-Swagger supports a clear assertion syntax to provide the best API test results. You can also get clean printing reports using this API testing tool.

Key Features:

  • If the swagger documentation is missing or it is erroneous, the test will fail

  • Offers readable assertion messages

  • Parameters are validated

Cost:

Free

22. Apiary Inspector

The Apiary Inspector tool monitors APIs when it is in the design phase. It captures the request and the response to do so. Apiary API tool allows its users to write API blueprints and view them later.

Key Features:

  • The control over API documents is role-based

  • You can add or remove a team member from the API design project

  • You get an API blueprint management dashboard

Cost:

Free

23. API Science

API Science tests web APIs and monitors their health and performance. It enables monitoring APIs that are private, public, and, partner. API Science lets you know if the API goes down and needs to be put back up.

Key Features:

  • It is powered by JavaScript

  • Supports XML, Oauth, JSON, and, REST

  • Manages API supply chain

  • Helps look into historical teens

  • Helps spot future issues using its reporting mechanism

Cost:

Basic at $29 per month, teams at $129 per month

24. Assertible

Assertible is one of the best API testing tools that focus on automation. It is known to be a reliable API tool for years now.

Key Features:

  • It supports automation of API at every step of the delivery pipeline and CI

  • You can create robust tests easily with this tool

  • API problems can be detected easily and quickly using Assertible

Cost:

The personal version is free, standard version starts at $25 per month

25. RESTSharp

RESTSharp is another API tool that tests REST APIs easily. It allows its users to develop and test .net APIs. It is handy to communicate with external data for Windows developers.

Key Features:

  • It is easy to use with its simple user interface

  • It supports synchronous and asynchronous requests

Cost:

Free

26. UniREST

UniREST is used to simplify creating HTTP REST requests. It is highly preferred by API testers because of its open-source feature. It is available in several languages which makes it popular among API developers. You can find different REST methods on UniREST’s own documentation page.

Key Features:

  • It supports 8 languages like Python, Ruby, Node, etc.

  • It can consolidate with BDD or XUNIT

  • You can refer to its documentation page for information

Cost:

Free

5 Things To Consider While Selecting The Best API Tool

1. Ease Of Use

The API testing tool that you choose needs to be easy to use, which means that even if you are an amateur with minimal training, you should be able to use that tool without much difficulty. The API tool should be visual and should provide simple functionality to complex actions.

2. Supported Technologies

The tool can’t work properly if it does not support all of the necessary formats and message protocols of the industry. With modernization at its peak, you need to make sure that the tool that you are using supports the technologies of the past, present, and, near future.

3. Optimized Workflow

It is important to check if your API tool has the ability to optimize your workflow. This includes intelligent mechanisms that can make your daily work like test creation, data entering, message flow, etc. simple.

4. Automation

You must consider if your API testing tool provides a mechanism that can run your tests in automation. If not, then you won’t be able to execute your test cases on-demand whenever required.

The tool that you select should have both, a command-line interface and available APIs to programmatically run your tests as a part of the continuous integration.

5. Maintenance

It is challenging to maintain and manage a large library of test cases. Your API testing tool should have the mechanism to understand which tests are available and the requirements of those API tests.

Your tool should be able to organize your test cases into a meaningful configuration that can support and validate the new application in various environments.

Conclusion

API testing has become quite popular over the last few years. It is important to choose the right and the best API tool for correct API solutions to achieve successful continuous integration. You can choose any one of the given API tools as per your requirements.

FAQs

What Is API Testing?

An acronym for Application Programming Interface, API essentially refers to the connecting layer between the backend database and the frontend user interface. API testing refers to the practice of directly testing the API, to confirm its usability, performance, reliability and to validate the desired output.

Thus, API testing is a crucial part of Integration testing, as it determines if the business logic is followed correctly, with the desired outcome.

Which Language Is Best For API Testing?

There are a ton of languages to choose from for API testing. However, these 5 languages are the most popular languages used for API testing:

  • Python

  • Ruby

  • Java

  • JavaScript

  • C#

Does API Testing Require Coding?

Automated testing needs you to make use of a testing tool that does not require coding, but manual testing needs code to test the API. It is recommended that you use automated API testing for better and quicker results.

Top 26 API Testing Tools...
StartupStash Team

The world's biggest online directory of resources and tools for startups and the most upvoted product on ProductHunt History.