17 Best API Testing Tools Reviewed For 2024

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.

Apache JMeter is a desktop application that allows you to measure test performance of applications across browsers and mobile OSs. The tool focuses on loading testing and provides an intuitive user interface. Apache JMeter is also capable of carrying out other testing types such as functional testing.

Apache JMeter can turn on/off variables depending on your target testing environment, which allows you to configure your test cases easily. The tool allows you to identify the issues in your performance by scaling your tests and rerunning existing scripts.

Apache JMeter also allows you to run stress tests so you are able to find breaking points in your systems, ensuring their reliability.

Apache JMeter is fully open source and free to use.

Subject7 makes becoming an automation expert accessible to anyone through its codeless automation. Thereby, leveling the playing field when it comes to API testing.

It is an exceptional automation tool for both technical and non-technical users in addition to reducing maintenance for QA engineers and testers. You can create easily create robust test flows with widget definitions, AJAX calls, and configuration templates across a library of over 100 hundred platforms, android, and iOS devices.

Whether it’s web or native app testing, Subject7 simplifies the process by enabling test authoring and running of sophisticated API automation tests a breeze. It incorporates a wide range of end-to-end test capabilities that encompass desktop, web applications, web services, mobile, security, load testing, and much more.

Subject7 is capable of delivering robust testing capabilities that scale adequately while providing enterprise-grade security, whether it’s on-premises or in the cloud.

The adaptability of Subject7 lies in its ability to provide GUI interfaces to interact with a wide range of automated commands, at a minimum, eliminating the need to write java codes. In addition, it provides several in-built commands to perform interactions for web and desktop applications.

It uses both open APIs and native to seamlessly facilitate integration with existing Agile tooling and DevOps ecosystems.

Unfortunately, Subject7 doesn’t provide any free version or free trials for users to test out its features before deciding to make a purchase. Its Professional plan is reasonably priced, although it requires an annual subscription of $250 USD per user/month. Both its Enterprise and Private Cloud plans provide customized pricing upon request.

Apigee Edge allows developers to test API proxies with ease. Apigee Edge enables API architects to build these API proxies – gateways or intermediaries so programmers can rapidly develop business solutions.

It provides robust API management functionality by wrapping your API with a proxy layer. If your application lacks an Apigee, it means its API is called directly by other APIs that want to consume its services.

Therefore, Apigee Edge provides developers with several abstractions and mechanisms so they don’t have to consume the services they need directly. This provides great security implementations for APIs, so you can share services without exposing your code.

In addition to scaling and analyzing your API, Apigee Edge also provides API authentication and monetization.

Apigee Edge provides users with the flexibility of not having to use any domain-specific language but extracting response data with either XML or JSON.

Apigee’s Evaluation plan is free. For its paid plans, customized pricing is available upon request.

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.

Hoppscotch is a free, open-source tool and API request builder. Hoppscotch provides REST API testing via a GUI API client to make HTTP requests and validate API request responses.

Incidentally, it was built as an alternative to Postman. And compared to other API frameworks, Hoppscotch has a more minimalistic, less distracting interface. Hence, Hoppscotch enables you to write test scripts with minimal distraction so requests are created faster.

For instance, Hoppscotch has a feature called Collections, which allows testers to group and save all the HTTP requests belonging to a single API endpoint together in a logical, organized manner.

Hoppscotch is an asset to API development environments because it allows developers to create HTTP requests in a logical, step-by-step manner. Especially when the API contains request objects with many layers of nested arrays and HTML objects.

Along with pre-request scripts, DevOp teams save precious time on their API development efforts. In addition to the REST services it provides, Hoppscoth also incorporates GraphQL to enable developers to retrieve descriptive data queries along with their API tests.

Therefore, Hoppscotch benefits resource-driven apps by ensuring the API is reliable and highly secure.

Hoppscotch is free but it accepts donations through PayPal and Patreon.