17 Best API Testing Tools Reviewed For 2024

Invicti is a web application and API security tool that helps organizations identify and fix vulnerabilities in their web assets. It combines automated discovery and security testing to provide a scalable solution for securing web applications and APIs. 

Invicti stands out as a robust API testing tool with its comprehensive feature set designed to address the multifaceted challenges of API security. One of the most notable features is its ability to cover all major API types, including REST, SOAP, and GraphQL, with built-in security checks. This versatility ensures that regardless of the API architecture in use, Invicti can provide thorough security testing. Additionally, Invicti supports a wide range of API definition formats, such as Postman, OpenAPI (Swagger), WADL, and WSDL, which simplifies the process of importing and testing APIs.

Another significant advantage of Invicti is its automated authentication capabilities. The tool supports popular API authentication methods, including basic HTTP authentication, JSON Web Tokens (JWTs), and OAuth2, which are essential for accessing and testing APIs securely. This feature is particularly beneficial in environments that use single sign-on (SSO) or multi-factor authentication (MFA), as it ensures that the scanner can authenticate and test APIs without manual intervention.

Integrations include MuleSoft Anypoint Exchange, Amazon API Gateway, Apigee API hub, Kubernetes, Azure Boards, Bitbucket, Bugzilla, FogBugz, DefectDojo, Freshservice, GitHub, GitLab, Jazz Team Server, and Jira.

Pricing is available upon request.

Acunetix is a web application and API security scanner designed to automate security testing, identify vulnerabilities, and facilitate efficient patching. Leveraging advanced technologies like DeepScan, it can analyze complex, dynamic websites built with HTML5 and JavaScript. 

Acunetix stands out with its ability to automatically discover and test APIs without disrupting development workflows. This is achieved through its zero-configuration setup, API management system integration, and network API discovery capabilities. It can detect over 12,000 vulnerabilities, including those listed in the OWASP Top 10 and API Top 10, and provides actionable scan results.

Additionally, Acunetix supports various formats for importing API definitions, such as WADL, Swagger, HTTP Archive (HAR) files, Postman files, and more, making it versatile in handling different API structures. Its ability to integrate with development processes and scan hard-to-reach places further enhances its utility.

Integrations include Azure Boards, BitBucket, Bugzilla, DefectDojo, FogBugz, Freshservice, GitHub, GitLab Issues, Invicti Standard, Jazz Team Server, Jira, and Kafka.

Pricing is available upon request.

Testim is touted as the first automation testing tool to use AI and machine learning. It flattens the time used for testing by recording every action you take and can subsequently turn these into tests in a matter of minutes.

Testim allows you to create stable tests quickly, easily, and accelerate product releases. By using its machine learning algorithm, it analyzes your app and knows which actions to perform when changes are made to your codebase. Therefore, Teslim helps QA teams reduce the need and burden of tedious test maintenance.

There are several tools to automate manual testing but if their pace is too slow, with ramping-up authoring posing significant bottlenecks, then it’s time to consider Testim. Testim allows you to create the most resilient end-to-end test with fast iteration that leverages AI-powered automation.

It comes with robust debugging tools that allow testers to troubleshoot quickly and diagnose failed tests.

it gives you operational control to scale and expand testing without sacrificing test quality. Testim integrates with other popular third-party systems such as Trello, TestRail, Github, and Jenkins. It also provides a modern JavaScript API to enable you to debug, refactor, and customize tests. Testim allows you to export test results with CSV into spreadsheets like Excel.

Testim’s Community plan is free. For its paid plans, customized pricing upon request for its Essentials and Professional plans.

Reflect is an AI-powered automated regression testing platform with API testing built-in. With Reflect, you can effortlessly create robust end-to-end tests without the need to write a single line of code. You are able to perform API tests and UI tests in tandem for a complete, end-to-end testing solution.

Enable your entire team to contribute to the testing effort effortlessly by adopting a no-code approach for constructing API tests, supporting XML, JSON, REST, and GraphQL-based APIs. Combine API testing with end-to-end regression testing for robust outcomes, easily setting up tests with direct API calls, and validating results through API validations, avoiding the need for scripting UI tests for third-party or internal systems. With Reflect's no-code test builder, extract values and add assertions seamlessly using a user-friendly interface, making API testing accessible to everyone without the requirement of coding knowledge.

Reflect's API Testing feature is not intended to replace API tests written in tools like Postman, REST Assured, or directly in code. Instead, it offers an easy way to incorporate direct API calls into your end-to-end tests, simplifying and streamlining the process. For instance, when testing a workflow that involves deleting an existing record, you can use API calls to create the record, making the test more concise and focused. By avoiding unnecessary UI steps, your tests become faster, more maintainable, and efficient, while still achieving repeatable and reliable results.

Integrations include Azure DevOps, Bitbucket Pipeline, CircleCI, GitHub, Actions, Heroku, Gitlab CI/CD, Jenkins Pipeline, Coherence, Webapp.io, Travis CI, Jenkins-X, Codefresh, and AWS CodeDeploy.

Reflect offers customized pricing on request and has a free demo for new users. You can try Reflect for free with 30 minutes of test coverage, unlimited test creation, and 5 users.

Katalon Studio equips DevOps and testing teams with several features to ensure they have a robust strategy to produce well-tested applications.

It is immensely flexible, allowing you to run tests on all platforms, whether desktop, web, or mobile. It can be used on various OSs like Linux, macOS, and Microsoft Windows. Katalon also permits you to run automated tests on UI elements such as pop-ups, iFrames, overlays, and so on.

One of Katalon Studio’s selling points is that it allows you to create and reuse automated scripts without going through the arduous process of writing code. While this codeless experience is a boon for beginners, it also provides sophisticated extensions and plugins for experts.

Moreover, Katalon gives you out-of-the-box, ready-made seamless integration with DevOps pipelines and CI testing tools. These factors help to drastically reduce the time necessary to create automated scripts.

It also provides several ways to customize and enhance your test procedure to fit your application’s context. These include keyword-driven testing, page object model testing, data-driven testing, and TDD/BDD Testing.

It provides support for the command line and other execution environments. It also supports Groovy, a language that is Java domain syntax compatible.

Katalon Studios comes with a free version but it doesn’t provide support for API monitoring in any of its products. Moreover, its paid plans are prohibitively priced, with Runtime Engine and Studio Enterprise costing $1,499 USD per license/year and $1,899 USD per license/year respectively.

Sauce Labs is a comprehensive continuous testing cloud for web and mobile applications that allows you to complete both manual and automated testing through a variety of testing channels. The tool provides a real device cloud so you can test across multiple devices. Sauce Labs also offers enterprise security and a proprietary data center.

Sauce Labs offers a variety of automated and manual testing methods, ensuring full test coverage of your applications. The tool provides a cross browser testing feature, which allows you to test end-to-end on various browsers. Sauce Labs also offers the ability to complete automated mobile testing so you can write tests for various devices to ensure your application runs smoothly.

Sauce Labs offers integrations with platforms such as Github, Jenkins and Bamboo, as well as chat applications such as Slack.

The cost of Sauce Labs starts at $39/month for the Live Testing package. The tool also offers a 28-day free trial.

Smartbear is a simple, yet scalable GUI test automation tool that focuses on desktop, web, and mobile testing. These modules allow you to recreate repeatable tests easily across various platforms, environments, and multiple devices.

Smartbear’s TestComplete feature offers automated UI Testing works across a diverse range of desktop applications, whether they’re built on Windows, or designed with WPF, Java, .Net, or other software languages. It makes continuous testing a breeze by enhancing your ability to run automated tests with test scripts, along with providing record and replay capabilities.

Smartbear’s Cross Browser Testing provides an all-in-one web testing platform for cross-browser compatibility. So, when it comes to web applications, Smartbear allows you to design reusable tests and run parallel execution tests for several platform browser configurations like chrome, including JavaScript frameworks like Angular and React.

Its ReadyAPI solution allows test engineers to accelerate API quality through web services like GraphQL, RESTful, and SOAP.

To add to its strong suite of test products, Smartbear acquired the open-source Cucumber, thereby merging the latter’s leadership in a behavior-driven development (BDD), especially among agile teams, with its expertise in test automation.

Smartbear’s TestComplete and ReadyAPI modules are expensive.

TestComplete Base offers Desktop, Mobile, and Web options; and it allows users to mix and match these according to their needs and affordability. Choosing the Desktop option alone starts at $5,438 USD. Mobile alone costs $6,158 USD, while the Web option by itself starts at $5,438 USD.

ReadyAPI Test is an easy-to-use, no-code API testing tool designed to streamline your testing workflows. ReadyAPI Test is a module within the ReadyAPI platform that gives small and enterprise development teams a next generation API testing solution to create, run, and analyze complex validation of REST, SOAP, & GraphQL APIs, JMS, JDBC, and other web services.

ReadyAPI Test is built to satisfy a wide range of technical expertise. The visual editors and wizards make testing a breeze for junior testers and senior developers alike. Point and click functionality lets you easily add assertions to tests by simply right-clicking and choosing one of our built-in assertions. The Smart Assertion engine will learn from your API responses and intelligently create assertions to give you maximum test coverage. ReadyAPI Test is perfect for teams seeking better workflow testing solutions and improve collaboration between testers and developers.

Whether you are using static build servers or dynamic, cloud based platforms, ReadyAPI has an exhaustive range of integrations into automated environments of any type. It has Native support for Git, Docker, Jenkins, Azure DevOps, TeamCity, and more. It allows command-line support for automated testing configuration on fixed machines. Plus, it allows control of which environment tests run on (i.e. development, QA, staging, etc.).

ReadyAPI Test Module starts at $759/license/year and offers a 14-day free trial.

SoapUI is an immensely popular API tool offered by SmartBear and includes ReadyAPI and TestEngine in its product suite. However, its popularity stems from the open-source technology at its core and its array of advanced tools.

One of the main factors driving its popularity is the fact that it both supports REST services and SOAP APIs. In addition to these, SoapUI’s ReadyAPI provides end-to-end testing for widely adopted protocols like GraphQL, Java Database Connectivity (JDBC), Java Message Service (JMS), and other APIs.

With TestEngine, SoapUI enables you to run test suites at a tremendous scale and in parallel to accelerate delivery pipelines.

SoapUI is a robust cross-platform solution that allows you to engage in various testing methodologies. It is widely adopted because it covers the whole gamut of the testing spectrum, ranging from functional API testing, load testing, security, and API mocking.

SoapUI comes with a Pro version and a free, open-source version.

ReadyAPI has three modules, namely API Test Module, API Performance Module, and API Virtualization priced at $759 USD per license, $5,639 USD per license, and $1,060 USD per license respectively. They are billed annually and provide 14-day trial periods.

Parasoft provides software engineers and DevOps with a comprehensive suite of software testing and QA platforms. It provides a range of solutions, starting from software development to testing automation that is powered by artificial intelligence.

Parasoft SOAtest simplifies the complexity of testing through visual drag-and-drop mechanisms to facilitate scriptless API Testing without writing a single line of code. It covers testing needs ranging from unit testing to functional and load testing across APIs and HTTP requests.

Unlike most API testing tools that predominantly handle REST API test cases, the Parasoft SOAtest module takes care of both REST and SOAP web services. In contrast to most automation tools, Parasoft allows you to integrate C/C++ tests into your software development environment through an IDE, in addition to containerized deployments, and CI/CD pipelines like Jenkins.

Overall, Parasoft SOAtest makes it easier to automatically enforce industry compliance, especially by its ability to early detect defects. As its name suggests, Parasoft Virtualize provides API virtualization that provides DevOps with deep insights through informative diagrams, detailed reports, and dashboards.

However, Parasoft is a bit complex to get started with but it more than makes up for that by enabling DevOps teams to implement quality assurance and security across the software development lifecycle.

Parasoft SOAtest doesn’t have any free version or free trial. Pricing is provided upon request.