What is API Testing

 API Testing is a software testing type that validates Application Programming Interfaces (APIs). The purpose of API Testing is to check the functionality, reliability, performance, and security of the programming interfaces. In API Testing, instead of using standard user inputs(keyboard) and outputs, we use software to send calls to the API, get output, and note down the system’s response. API tests are very different from GUI Tests and won’t concentrate on the look and feel of an application. It mainly concentrates on the business logic layer of the software architecture.

API Testing : As we know API stands for Application Programming Interface which acts as an intermediate of communication between two applications. Due to this intermediary role of API (Application Programming Interface) two applications talk to each other and performs the required actions efficiently. API contains a set of rules and guidelines based on which the applications are developed. So in simple we can say an API acts as an interface between two software applications so that two software applications can communicate with each other.

API (Application Programming Interface) testing is a type of software testing that focuses on the functionality, reliability, and performance of application programming interfaces (APIs). APIs act as a bridge between different software systems, allowing them to communicate and exchange data with each other.

API testing is important because it helps ensure that the different systems that make up an application are working together correctly and that the data being exchanged is accurate and secure. It is also important because it helps identify and fix issues before the application is deployed to production.

Types of API testing : 

• Functional testing: Testing the functionality of the API to ensure it behaves as expected
• Security testing: Testing the security of the API to ensure it is protected against common vulnerabilities
• Performance testing: Testing the performance of the API to ensure it can handle the expected load
• Interoperability testing: Testing the compatibility of the API with other systems
• Usability testing: Testing the usability of the API for developers.

API Testing Tools  :  Postman, SoapUI, and Runscope  etc.

API testing includes the following steps:

• Reviewing the API documentation to understand the functionality and expected inputs and outputs
• Writing test cases that exercise the different functionality of the API
• Executing the test cases and comparing the expected results with the actual results
• Analyzing the results and identifying any issues that need to be fixed