In API testing, API means application programming interface. It is a common functionality a web API provides a way to access the API functionality from the application or website through a set of API calls. API testing ensures that all API calls are tested for correct behavior and provide correct response as an output.
API Testing is a very important aspect of the QA process of software development. Any type of application uses APIs, whether they’re internal or external. Even an app which does not use any API calls at all will make use of some sort of protocols and APIs.
Karate DSL
Creating scenarios for API-based BDD tests has never been easier. Karate DSL helps users accomplish this without needing to write down step definitions. It also has already created those definitions, so users can get on with API testing as quickly as possible.
Features
Version 0.9.6 of Karate DSL includes async capability-based support for WebSocket. It offers easy-to-write tests for those who aren’t into core programming, as well as support for multithreaded parallel execution and configuration staging/switching. In addition, because the tool is built on top of Cucumber-JVM, you can execute test cases like any project developed using Java. Only, instead of Java, you have to write scripts in a language that makes it easier to work with JSON or XML.
Pricing
Karate DSL has open-source pricing. This means that it will provide the software free of charge. However, the solutions will have costs according to the requirements.
Rest Assured
Rest Assured is an API tool that facilitates easy testing of REST services. It’s an open-source tool and a Java domain-specific language designed to make REST testing simpler. Moreover, the latest version has fixed OSGi support-related issues. It also offers added support when it comes to using Apache Johnzon.
Features
Beginning with version 4.2.0, Rest Assured requires Java 8 or higher.
Rest Assured has the following characteristics:
- Built-in functionalities ensure that users don’t need to carry out coding from scratch.
- Users don’t require extensive knowledge of HTTP.
- A single framework can have a combination of REST tests and UI.
- Seamless integration is possible with the Serenity automation framework.
- Provides several authentication mechanisms
Pricing
Rest Assured has open-source pricing. This implies that the software is free, but not the solutions.
Testim
Testim is actually a full blown test automation platform, a subset of which includes API testing. The intriguing thing about Testim is that it uses artificial intelligence to help with test suite execution, maintenance, and even creation. Part of this, of course, involves testing your API.
Features
Obviously, the killer feature here is a framework that learns with each test suite execution and maintenance activity. But, on top of that, you can create API actions and validations for standard testing activities. But you can also isolate your UI testing by extracting data from your API and efficiently exercising the user interface. It’s a powerful way to test the UI and API in parallel.
Pricing
Testim has a freemium model, making it easy to get started for free. From there, you can customize the pricing to your team’s needs.
Assertible
Developers and testers widely perceive Assertible as one of the top API testing tools with a high focus on reliability, considering it supports API tests at every step that goes from continuous integration to the delivery pipeline.
Further, Assertible provides users with very useful features. It supports integration with GitHub, Zapier, and Slack. Additionally, Assertible also validates HTTP responses with turnkey assertions.
This API testing tool offers three different packages. The standard version costs 25$ per month; the startup plan is 50$ per month; the business plan is the most expensive package (and the one that offers more features), which costs 100$ per month. Moreover, there is also a free personal plan that is suitable for executing more manageable API tests and understanding how Assertible works.
Apigee
Apigee is a very interesting cross-cloud API testing software powered by JavaScript that allows developers and testers to access its features via different editors.
This tool is compatible with APIs that contain large amounts of data, being ideal for robust and complex digital businesses. Plus, it is able to easily identify issues that are compromising performance by analyzing the API traffic, response times, and potential error rates. Moreover, Apigee also enables the creation of proxies from Open API Specification.
Apigee provides a free trial, which allows taking it for a test ride before making any decisions. Afterward, to continue using it, organizations and testers must choose the most suitable package. The existing packages are Evaluation, Standard, Enterprise, and Enterprise Plus.
SoapUI
SoapUI is a software tool 100% dedicated to API testing that enables executing tests on SOAP APIs and also on web services REST, considering that it is headless. It is often one of the preferred tools by testers since it allows them to create complex scenarios and further supports asynchronous testing. Plus, it also stands out for its great data-driven testing and easiness of use.
SoapUI offers two packages, one free and the other paid (the pro package). The free solution is fairly easy to use, and testers can reutilize scripts. In the pro package, it is additionally possible to create custom code, extract data (from databases, files, and excels), and support native CI/CD integrations.
Katalon
Katalon is a popular test automation tool for APIs, as well as web applications and desktop and mobile apps. It supports SOAP and REST requests and provides multiple parameterization features and commands. Additionally, Katalon follows a data-driven approach, supports CI/CD integrations, and allows testers to execute automated and exploratory testing.
One of the greatest advantages that this software has is that, despite the numerous useful features it offers, it is not very hard to use, being suitable even for non-techies.
Katalon offers a very good and complete free package. Additionally, users can also opt for Studio Enterprise (76$/month), which includes extended features and private plugins. As an alternative, there is also the Runtime Engine package (54$/month) that further executes tests in CI/CD pipelines or via the command-line interface.
Postman
Although it was built as a plugin for Google Chrome, Postman can also be used with Windows and Mac and is an excellent tool for testing API services, including monitorization, debugging, running requests, etc.
Postman does not require developers or testers to learn a new language and further supports various formats (such as Swagger and RAML). Moreover, it also provides built-in tools, workspaces, and collections. Contrarily to CURL, Postman is not a tool based on the command line; thus, developers and testers do not need to paste the text into the command line window.
Postman is a free API testing tool. For those who wish to benefit from additional features, then it costs 12$ per month for each user.
Tricentis
Tricentis is one of the top choices for those who wish to integrate it into the Agile and DevOps Cycle. It follows model-based test automation, which facilitates script maintenance, and provides a fast time for regression testing.
One of the primary pros is that it supports multiple protocols, such as REST, SOAP, HTTP(s), MQ, JMS, NET TCP, IBM MQ, etc. Another great plus is that Tricentis allows end-to-end testing across mobile, cross-browser, and packaged apps.
Regarding the pricing, it may vary according to the specifications of each package.
Conclusion:
Almost every business today makes use of APIs. An API is an application program interface, and it defines how two programs can communicate with each other. It’s basically a set of rules and standards which describe the data structure and the format in which data is transmitted between applications.