Before we dive straight into the comparison between the best API testing tools, let’s start with what is an API & API Testing.
Simply put, the way two or more computer programmes communicate with each other is called Application Programming Interface i.e. API. In context, the term ‘Application’ means any software with a distinct function, and ‘Interface’ can be thought of as a contract of service between two applications.
To test APIs means to check that the application’s functionalities are working the way they are intended to. The tests are performed either directly on the API or as part of integration testing. API automated testing is essential for CI/CD workflows and product quality. API tests can withstand rapid change and short release cycles without compromising the test results.
What are the benefits?
Finding bugs at an early stage of software development Having access to the application without a user interface or users to engage with the system is a significant advantage of API testing. In other words, QA testers don’t have to be familiar with the software programme to execute API tests. This is a huge benefit because it gives QA engineers early insight into flaws and faults, allowing developers to fix them before they have an impact on the interface.
Effective use of time & reducing test costs One of the biggest distinctions between API and UI testing is that functional UI testing takes far more time than API testing. The polling of webpage elements required for UI testing can significantly slow down the testing process. And one of the best things about API testing is how quickly it produces results! Moreover, early flaw diagnosis and quicker results from API testing result in lower total testing expenses.
Non-attachment to programming languages XML or JSON is used to communicate data during an API test. Because these transfer modes are entirely language-independent you can use any core language when you’re looking to automate API testing for your application.
Improved test coverage Automated API tests typically cover a wider range of functionality than unit tests, which focus on a single component, function, or method of the source code. Mostly, issues frequently develop where two modules meet and one level’s scope finishes and another level’s begins. The purpose of API level testing is to verify that each system component operates as expected. This enhances the software’s overall quality and the way in which it interacts with users.
5 best API automation tools out there
1. HyperTest
HyperTest is the only API testing platform that is truly no-code. It regresses all your APIs by auto-generating integration tests using your network traffic without asking teams to write a single line of code, also giving a way to reproduce these failures inside actual user-journeys. HyperTest tests a user-flow, across the sequence of steps an actual user will take in using the application via its API calls. HyperTest, by design, makes it impossible for devs to introduce a breaking change that is not reported back to QA teams. It detects every issue during testing in less than 10 mins, that other written tests would definitely miss.
Key Features:
End to end backend testing
Automatic Test case Design
Automatic test case maintenance
Self healing API tests i.e. auto – updation
Self-generated assertions
API coverage Reports built within
Integration with any CI/CD tool like Jenkins, Circle CI, GitLab etc
Automatic documentation of APIs and schemas
Performance testing of APIs
2. Postman
Postman is an API development environment which is divided into three parts – Collections, Workspaces, and Built-in Tools. Postman collections will allow you to run requests, test and debug, create automated tests and mock, document, and monitor API. It will also allow you to share the collections, set permissions, and manage participation in multiple workspaces. Built-in tools will provide the features which will be required by the developers to work with an API.
Key Features:
Helps in automated testing, however still requires some coding
Assists in exploratory testing
It supports Swagger and RAML (RESTful API Modeling Language) formats
It supports knowledge sharing within the team
Run, test, document, and monitoring features
3. Katalon
Katalon Studio is an automation tool for API, Web, Desktop testing and Mobile testing. It provides easy deployment by including all frameworks, ALM integrations, and plugins in one package. The capability of combining UI and API/Web services for multiple environments (Windows, Mac OS, and Linux) is also a unique advantage of Katalon Studio among the top API tools.
Key Features:
Supports REST, SOAP requests, and SSL client certificates
AssertJ support to create fluent assertions in BDD style
Enable test import from Swagger (2.0 & 3.0), Postman, WSDL, and WADL
Support API test data setup using UI testing
Can be used for both automated and exploratory testing
4. Apigee
Apigee is a 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.
Key Features:
Allows design to monitor, implement and extend API
It is multi-step and powered by Javascript
Define performance issues by tracking API traffic, error rate, and response time
Easily create an API proxy based on open API specifications and deploy it in the cloud
5. JMeter
JMeter is open-source software for load and performance testing of applications. It supports cross-platform and works at a protocol layer. Developers can use this tool as a unit-test tool for the testing of JDBC database connections. It has plugins based architecture. JMeter can generate test data, and supports Command-line mode, which is helpful for Java-compatible OS.
Key Features:
Cache and offline replay of test results
Automatically work with CSV files, thus enabling the team to create unique parameter values for the API tests at speed
Able to include the API tests in CI pipeline thanks to JMeter and Jenkins integrations
Available for both static and dynamic resources performance testing
To sum it up, here’s a comparison snapshot of all the 5 tools
The Only Tool You Need to Test Your APIs
While these are some really great tools, HyperTest is the only API testing platform that requires no code. Moreover, it guarantees over 95% coverage of your application in less than 5 minutes. Its unique approach to API regression discovers every API error for developers before release. If you’re building a software, you need to use HyperTest, it is by far the best API testing tool. Schedule a demo to understand how it can help you ship out bug-free products in minutes.