Top API Testing Tools for Developers

Have you heard of API testing? Wondering what API testing tools are? Well, API testing can be defined as a type of software testing that focuses on determining if APIs meet your development expectations.

So, it is all about inspecting if the applications meet the precise functions, performance levels, consistency, and safety outlooks.
API testing has become vital for all software companies. As per Google Trends, the focus on API testing has boosted in the previous few years.

As there is no graphic UI, testing performance on the front end is tough. However, API has become pretty significant for software development.

Here are some of the top API testing tools mentioned below, which you can count on for your projects.

1. Postman
   If you remember, then you would know that Postman was introduced as a Google Chrome plugin. Its primary objective for it was to be a precise functional API testing tool. It has expanded its services to both Windows and Mac platforms.

   Compared to the other tools, Postman is one of the easiest to use. It is straightforward, enables diverse parameters, and has the explicit capability to store different commands. This tool comes with an interface that gives access to extract web API data.

   Other than that, it has built-in tools, collections, and workspaces which have proven to be quite helpful. It supports formats of different kinds along with RAML and Swagger. This valuable tool for API testing is free to use, and with the paid one, you will get to discover additional features.

   Read More:- Best Practices for REST API Development

2. Hoppscotch
   Hoppscotch commenced as a postwoman, a substitute for the free API testing tool, which was Postman. Far ahead, it was renamed and received 26,000+ stars on GitHub.

   It is one of the most lightweight tools that you would come across with a minimalist user interface. Having numerous features and functionalities, it facilitates sending and receiving of data sets with the assistance of the SocketIO server.

   Furthermore, it has an open full-duplex communication channel over one TCP connection and also allows sending graphic queries. You can also stream server-sent events over the HTTP connection, besides publishing and subscribing to the topics of the MQTT broker.

3. Tricentis Tosca
   Tricentis Tosca is an API testing tool that assists in conducting continuous testing for technologies related to DevOps and Agile.

   It aids in dipping the time of regression testing and realizing workable automation with new technology. The exceptional outcome and dashboard give a remarkable view of the outcomes.

   Tricentis Tosca maximizes reuse and maintainability with model-based test automation. The API tests can be used not only on mobile but also on cross-browser and packaged applications. Moreover, it supports different types of protocols, including JMS, AMQP, Rabbit MQ, SOAP, REST, IBM MQ, NET TCP, and others.

4. Rest Assured
   Rest Assured is an API automation testing tool that offers effortless testing solutions for the precise REST services. As an accurate open-source tool, it has a Java domain-based language that is crafted to make the procedure of REST testing effortless.

   It comes with in-built features that do not necessitate one to initiate programming right from scratch.

   Also, one does not require a prerequisite to have an extreme acquaintance of HTTP to work with this precise tool. With the aid of the Serenity Automation framework, this rest API testing tool makes amalgamation likely and effortless. Also, it provides numerous and valuable authentication mechanisms to work with.
   Read More:- Software Development Tools

5. Ready API
   Ready API is facilitated by Smartbear and is one of the most used API testing tools. Besides being a web service launcher, this tool has the potential to analyze the results straight from the dashboard.

   It makes sure that comprehensive quality cross-checks for all the web-based services are done and disregards involved dependences.

   Furthermore, it also supports API testing integration with the CI / CD pipeline. Ready API is a four-in-one tool, which offers features like assimilating API performance testing, API functional testing, API virtualization, and API security testing.

6. JMeter
   JMeter was developed to comprehend load testing and is leveraged for functional API testing. It provides functionalities such as precise bug fixing and core-based improvements and works effectively with CSV files.

   This open-source API testing tool creates an integration between JMeter and Jenkins, allowing users to add API tests within the CI pipelines.

   It can be leveraged in static and dynamic resource-based performance testing and enables to replay of the outcomes. JMeter also supports per-thread cookies. Besides that, it allows the team to build unique test parameter values.

7. API Fortress
   API fortress is an explicit tool that crafts and automates performance levels with functional testing solutions. It is measured in the list of best API testing tools for REST and SOAP.

   With robust notification and data integration, API Fortress comes with regression testing too. The tool is simple in usage and removes redundancy. It also helps firms to enhance transparency levels.

   It comes with a flawless UI and seems to be the finest tool for those who have no technology background. With this tool, you get a one-click test integration function, which is totally compatible with cloud and physical hardware too.

8. RestSharp
   Restsharp is a precise API testing solution that supports building .Net APIs and then testing them with similar tools.

   It is relatively convenient for Windows developers who leverage REST and SOAP APIs for interacting with the exterior data sets.

   This tool is straightforward to comprehend and effortless to use. It backs asynchronous and synchronous requests deprived of much distress.

9. Rapid API
   Rapid API is declared one of the largest and most popular automated API testing tools of today’s time.

   With this tool, you can effortlessly search, test, and connect thousands of APIs using just one account. It also allows the users to collaborate easily with external and internal APIs with the help of Rapid API for teams.

   The best part about this tool is that it is free to use and can test as many APIs as you want without restriction. It has crafted one workspace for numerous public APIs, which is really tough to find in any other testing tool.

10. SoapUI
    SoapUI is a precise on-prem API testing tool that offers seamless access to the programmers to test and use SOAP, REST, GraphQL, and web-based services. With the assistance of this software tool, the programmers and testing teams can craft an extremely commanding solution.

    They are also given the power to run and analyze complex tests on web services, and while talking about its features, then it is almost unthinkable and powered with exceptions.

    The testing tool allows one to test reports, SOAP API testing, and create custom codes with the help of Groovy.

    In addition to that, it facilitates transferring data sets from one response to another API calls without physical effort.

    Moreover, the best part about using Soap UI is that it does not bring any changes to the work. So, all the things will be stored, and you can commence from where you were standstill.

    Lastly, these most powerful tools for REST and SOAP APIs come in two packages. The first is the free package, where users get access to the complete source code. At a similar time, the fixed one comes with modernized functionalities, which take API testing to the subsequent stage.

11. Citrus
    We are introducing you to the next automated testing tool on the list called Citrus. It comes with precise messaging protocols, data formats, and helpful documentation.

    The tool can also test SOAP, HTTP, JMS, and REST. This tool can quickly achieve your quality, function, and stability goals.
    Furthermore, when it comes to integration testing, it can automate the process virtually for any messaging protocol apart from the data format. It also has a robust validation mechanism for XML message contents and offers trouble-free migration from development to production.

12. Assertible
    Assertible is an open-source tool that concentrates on reliability and automation along with GitHub forms. It comes with the sync feature, which further gives users the ability to update their tests whenever changes are made to the specifications.

    This tool backs the automation of API tests right at each stage of the explicit continuous integration and precise delivery pipeline. It offers support for operating the API tests after deployment and integration with familiar tools like Slack and Zapier.

    Furthermore, Assertible reduces the application’s bugs by giving users access to create an Automated QA system.

13. Katalon Studio
    It is a free It is a free testing automation tool that one can use for various purposes, such as to test web applications, standalone apps, mobile apps, and more.

    Ever since this tool was launched, it has gained acceptance for being the most projecting tool for API and web-based services testing. It also supports SOAP and REST requests besides various commands and parameterization features.

    Katalon Studio is perfect for both professionals and people with less technical knowledge. Furthermore, the tool backs data-steered tactics that enable CI/CD integrations and automatic investigative testing. Undoubtedly it is a complete package and a framework you can count on.

14. Testim
    A tool that is a test automation platform with a subset of API testing is Testim. The fantastic feature of this tool is that it uses artificial intelligence to help with the test suite, execution, maintenance, and building.

    With the top API management features, Testim helps create API actions and even validations for standard testing activities. It is also likely to detach the UI testing by fetching the data sets from API.

    Not to mention, this tool is a powerful way by which you can test the UI along with the API in a parallel manner. The tool comes with a freemium model and allows users to customize the pricing as per your organization’s requirements.

15. Karate DSL
    If you are tired of writing down the step definition, then Karate DSL is a tool you should check out. This tool helps to create scenarios for API-based BDD tests without any hassle.

    You will get access to those definitions and operate testing without any problem. It offers simple-to-write tests for those who have a lesser acquaintance of development.

    Besides that, it completely supports multithreaded parallel execution and configuration switching too. Karate DSL allows users to execute tests on any project using Java as it has been masterfully built on top of Cucumber JVM.

16. Paw
    This API performance testing tool has been specially designed for Mac. It is perfect for API makers and consumers as it helps build HTTP requests and has an excellent interface.

    The tool is known for having a precise and steady performance when associated with others and comes with multidimensional environment settings. Using Paw, you can generate client codes and inspect server responses too.

17. Apigee
    Here comes the cross-cloud API testing tool called Apigee, which also offers API management features. It gives users the access to measure and test API performance besides supporting and building them with the help of Swagger.

    The developers have strategized this tool for digital business solutions and data-rich mobile-driven APIs. Apigee offers complete support to Node.js and helps to identify the performance issues by tracking API traffic, error rates, and response times.

    Moreover, it can create API proxies out of the Open API specification and finally bring them to the cloud environment through easy steps. The tool is driven by JavaScript and is deliberately built for digital businesses.

18. AirBorne
    If you are exploring a Ruby-based RSpecdriven API testing framework, consider Air Borne. This open-source testing tool does not have a UI and provides explicit text files to write down the specific codes.

    It works quite well enough with the rack applications like Grape. Moreover, the testers need to remember several key methods in the toolset and a few Ruby and Rspec fundamentals to use this tool.

19. Web Inject
    Introduce yourself to Web Inject, which can be defined as an open-source solution. It offers automated testing of web applications and web services.

    This specific tool can gather and analyze the outcomes to generate an automated report. It is written in Peri and can be easily installed on diverse platforms such as Linux, GNU, MS Windows, Solaris, and Mac OS.

    Users can use this tool on diverse platforms, leveraging the PERL interpretation effortlessly. Moreover, it creates fully automated test suites for functional, regression, and acceptance testing. Lastly, this is one of the most trusted tools in the market.

20. Fiddler
    Telerik has built Fiddler and is the foremost preference of many programmers and testers who generate and validate API exposed over HTTPS. It can also be launched as a free web debugging proxy for various browsers, platforms, and systems.

    With this specific tool, you can easily debug web-based applications by seizing networking traffic from online sources and test-based computers. It allows the users to monitor, manipulate and reuse HTTP requests and is perfect for Layman testers to proficient ones.

    The tool ensures that proper cookies, headers, and cache directives are transferred between the client and the server. The Fiddlers API composer makes it easy and quick to test, group, and organize the API requests.

    It also supports any framework, including Ruby, Java, and NET. Furthermore, Fiddler comes with .Net language for a more powerful add-on and is free to use. However, with the paid choice, you can access precise enterprise support.

Best Recommendations and Tips to Pick the Best API testing tool!

With so many selections in the marketplace, it must be tough to select the right one. Isn’t it? To favour your difficulty, here are some tips listed below to help you pick the best API testing tool.

• Ability to integrate – The tool should have the ability to integrate with a continuous integration pipeline.
• Sharing options – The tool you are selecting should have speedy sharing options along with options of synchronization for the teams.
• Generate API directly – Any tool you are choosing should have the potential to generate API documentation directly from the testing tool itself.
• Ability to improve execution time – When choosing a testing solution for API testing, make sure that it comes with the possibility to run asynchronous tests so that it can help in improving the execution time.
• User interface – It should have an easy-to-use user interface. Besides that, the tool should be able to group the API requests and organize them into collections.

Moving Forward: Get the best API tool now!

These were some of the perfect API testing tools for users having diverse requirements. The tools mentioned above are all great for testing REST, SOAP, or HTTP APIs besides making sure that no error is caused.

Some of them come totally free to use, while others have paid options available to enjoy the advanced features.

So, depending on the requirements of your organization, you can choose any one of the above tools without thinking twice.