Top 17 API Testing Tools for Software Testing Process

Relia Software

Relia Software

Quang Duc

Relia Software

Software Development

17 API testing tools include Postman, SoapUI, Katalon Studio, Apigee, JMeter, Rest Assured, Assertible, ACCELQ, ReadyAPI, Airborne, Pyresttest, Karate DSL, etc.

API Testing Tools

Table of Contents

APIs (Application Programming Interfaces) facilitate data flow and functionality in modern applications. However, comprehensive testing is needed to ensure API functionality. This is where API testing tools shine.

This article discusses 17 leading API testing tools with their varying features. We will show you how these technologies can help developers and testers construct trustworthy APIs that users can trust. 

Postman

Postman is a popular tool for API development, testing, and management. It has a user-friendly interface, a large feature set, and extensive support, making it a popular choice among developers of all skill levels.

Price

$12 per month

Website

https://www.getpostman.com/ 

Highlight Features:

  • Tests Many API Types:  Postman can test APIs that use different protocols, like HTTP, HTTPS, REST, GraphQL, WebSocket, OAuth, and SOAP.
  • Creates API Documentation: Postman can turn your tests into API documentation. Both API builders and users can benefit from this.

postman tool

SoapUI

SoapUI is a popular free and open-source web service tester. It works well with SOAP and REST APIs, which are used for application communication. 

Price

$65 per month

Website

https://www.soapui.org/ 

Highlight Features:

  • Tests Many API Types: SoapUI can test different kinds of APIs, such as SOAP, WSDL, REST, and GraphQL.
  • Creates Fake APIs: SoapUI may construct fake APIs for testing. This is handy if the real API is not ready or you want to test a specific component.

SoapUI tool

Katalon Studio

Katalon Studio debuts as a formidable competitor in the API testing space, providing a comprehensive set of capabilities aimed at streamlining the testing process.

Price

Free 

Website

https://katalon.com/ 

Highlight Features:

  • Makes Testing More Thorough: Katalon Studio can leverage external data to improve testing. This makes your tests more comprehensive and easier to manage.
  • Clear Test Results: Katalon Studio gives clear reports on your tests, including pass/fail, duration, and other details. This clarifies API operation.

Katalon Tool

Apigee

The Google Cloud API management platform Apigee is powerful. It includes tools for API design, security, deployment, monitoring, and analysis. Apigee can help major enterprises and startups manage APIs and provide great user experiences.

Price

Free

Website

https://cloud.google.com/apigee/ 

Highlight Features:

  • Test Workflows: Apigee can develop multi-step API tests. You can test your APIs in more sophisticated circumstances.
  • Tracks API Performance: Apigee may track API response time, traffic capacity, and failures. This helps you find and fix performance issues.

Apigee Tool

JMeter

JMeter is an open-source application performance testing software. It's popular for API, web, mobile, and other testing. JMeter imitates users sending requests to a target system and analyzes performance. This finds bottlenecks, measures response times, and ensures your app can manage traffic.

Price

Free

Website

https://jmeter.apache.org/ 

Highlight Features:

  • Performance Testing Expert: JMeter simulates big API loads well. You may stress-test your API using real-world usage patterns. This identifies and fixes bottlenecks before users are affected.
  • Multi-Protocol Master: JMeter supports HTTP, HTTPS, SOAP, REST, and more API protocols. Flexibility makes it appropriate for many testing projects.
  • Integration with CI/CD Pipelines: JMeter easily interfaces with popular CI/CD pipelines, allowing you to automate API testing as part of the development process. Continuous testing and fast feedback are ensured.

JMeter tool

Rest Assured

Rest Assured is a popular open-source Java API testing library. Building and running automated tests for REST-based web services is easier. Rest Assured helps developers and testers read, maintain, and enjoy API testing.

Price

Free

Website

https://rest-assured.io/ 

Highlight Features:

  • Simple to Use with Java: Rest Assured makes testing Java programs straightforward. Developers can write tests using their Java skills.
  • Testing using Less Code: Rest Assured streamlines API requests and checks. It reduces code writing and saves programmers time.

Rest Assured

Assertible

A cloud-based platform, Assertible simplifies API testing and monitoring. API developers and testers may utilize its user-friendly UI and comprehensive features to ensure API health and stability.

Price

$25 per month

Website

https://assertible.com/ 

Highlight Features:

  • Automatic Tests: Assertible runs API tests automatically while developing. This ensures your API works and your tests are always current.
  • Monitoring APIs: Assertible can monitor your API and notify you of issues. You can spot problems early and fix them swiftly.
  • Easy for Beginners: Assertible's visual interface makes test creation and management simple for non-coders.

assertible tool

ACCELQ

ACCELQ is a top cloud-based platform for API testing, automation, and management. It is designed to empower developers and testers with a codeless approach. Moreover, ACCELQ also speeds up API testing and ensures accuracy by using AI.

Price

Non-public

Website

https://www.accelq.com/ 

Highlight Features:

  • All-in-One Testing Tool: ACCELQ can test APIs for security, functionality, and performance under demand. You won't need numerous tools for different testing activities.
  • AI Aids Testing: ACCELQ speeds up test writing with AI. It can automatically construct API-specific tests.

ACCELQ tool

ReadyAPI

ReadyAPI by SmartBear simplifies API and web service functional, security, and performance testing. It provides developers and testers with a feature-rich environment to ensure API quality and dependability.

Price

Non-public

Website

https://smartbear.com/product/ready-api/ 

Highlight Features:

  • Tests APIs Thoroughly: ReadyAPI can test your API's functionality, security, and performance under high traffic.
  • Works with API Documentation: ReadyAPI helps you develop tests faster using API documentation. You may also share and reuse your tests.

Ready API tool

Airborne

Airborne grows as a comprehensive testing framework designed exclusively for the Ruby programming language. Airborne uses the RSpec testing suite to ease the process of designing and performing API tests.

Highlight Features:

  • Works with RSpec: Airborne works with RSpec, another popular Ruby utility. This implies you can utilize RSpec features to test thoroughly.
  • Checks JSON Responses: Airborne supports JSON APIs. Inbuilt features examine if answer data matches expectations.
  • Supports Many Request Types: Airborne can be used to test APIs that use different methods to send data like GET, POST, PUT, and DELETE.

Airbone tool

Pyresttest

Pyresttest is a lightweight and easy-to-use Python tool utility for speeding up API testing. It is aimed at testers and developers who appreciate simplicity and ease of use.

Highlight Features:

  • Simple Tools: Pyresttest only provides the tools you need to submit API queries, see answers, and see test results. It has a few puzzling features.
  • Performance Measurement: Pyresttest calculates API response time in addition to evaluating functionality. This helps you find API bottlenecks.
  • Linux and Mac: Pyresttest runs well mainly on Linux and Mac. There might be ways to make it work on other systems, but it's not officially supported.

Pyresttest tool

Karate Labs

Karate Labs is a sophisticated, open-source API testing framework that simplifies API testing. Karate DSL's natural language syntax makes tests easier to create, interpret, and understand than standard programming languages. Testers and developers can collaborate and reduce the learning curve for new users.

Highlight Features:

  • Focuses on API Calls:  Karate simplifies API calls by allowing you to focus on what data to give and what response to expect. This clarifies each test's purpose.
  • Tests with Different Data:  Karate may test your API with many different scenarios using data from other sources. This reveals further API flaws.
  • Can Fake Parts of Your API: Karate can test API components by creating fake versions. This lets you test parts of your API alone or pretend other systems are connected.

karate labs tool

Testsigma

Testsigma offers a single platform for API testing and other testing tasks. It supports testers with little coding skills and automation framework developers.

Price

Free

Website

https://testsigma.com/ 

Highlight Features:

  • Uses AI to Make Testing Faster:  Testsigma uses artificial intelligence (AI) to speed up testing. For example, it can automatically construct API-specific tests.
  • Can Do All Types of Testing in One Place: Testsigma tests APIs, mobile apps, websites, and desktop apps in one place. You can use one tool for all your testing instead of multiple.
  • Checks Thoroughly: Testsigma thoroughly checks API responses, including status codes, data, and content types. This checks API functionality.

testsigma tool

Insomnia

Insomnia, a robust open-source platform, handles API creation, testing, and debugging. Developers and testers benefit from its easy-to-use interface and extensive features.

Price

Free

Website

https://insomnia.rest/ 

Highlight Features:

  • Easy for Beginners: Insomnia's basic UI makes API testing easy for beginners.
  • Supports Many APIs: Insomnia tests HTTP, SOAP, and GraphQL APIs. So you don't need a tool for each API type.
  • Makes Building Requests Easy: Insomnia guides you through API request creation. You can specify the web address, method (GET or POST), and additional data.

insomnia tool

Cypress

Cypress is a popular open-source test automation framework that was created primarily for modern online applications. While Cypress is primarily designed for user interface (UI) testing, it also has unexpected API testing capabilities.

Price

Free

Website

https://www.cypress.io/ 

Highlight Features:

  • For UI Testers: Cypress makes testing APIs easy if you know how to test web pages. This reduces tool learning time.
  • Works with Your Existing Tests: Cypress can test APIs and web pages simultaneously. This delivers a more thorough picture of application performance.
  • Easy to Write Tests: Cypress writes tests in familiar Javascript code, making them easy to understand and adapt.
  • Built-in Requests: Cypress contains a command to send API requests from tests. It saves time and effort for developers.

cypess-javascript-frameworks.webp

API Fortress

API Fortress is a strong and comprehensive framework that streamlines API testing.  It offers developers and testers a feature-rich environment for API test building, running, and management.

Price

Non-public

Website

https://saucelabs.com/products/api-testing 

Highlight Features:

  • Automatic Tests: API Fortress can perform API tests during development. This lets you catch API errors early and often, saving time.
  • Specifications: API Fortress can test APIs created in various ways, including HTTP, SOAP, and GraphQL.
  • Security Checks: API Fortress can help you find and fix API security vulnerabilities before they become a problem.

api fortress tool

Citrus Framework

Citrus Framework integrates APIs, unlike typical API testing. This powerful open-source Java tool simplifies testing how different sections of your application communicate, notably message-based communication. 

Price

Open-source

Website

https://citrusframework.org/ 

Highlight Features:

  • Tests More Than APIs: Citrus can test how your application's components communicate, not simply with other websites. Applications that deliver messages benefit from this.
  • Simple to Write Tests (for Java programmers): Citrus writes tests in a way that makes them easy to understand and follow. This simplifies application testing for programmers.

citrus tool

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Conclusion

This article looked at a variety of API testing tools, showcasing their features for different purposes. From user-friendly options for novices to feature-rich platforms for extensive testing, there is a tool to help you design strong APIs. Remember that selecting the correct tool and prioritizing consistent testing throughout development is critical to ensure API quality and a smooth user experience.

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