Application Programming Interface or API has become a necessity as we move forward in time. Our technology is becoming more and more complex. Data, software applications and all resources are a big part of this complex. API has become a big part of the widespread distribution of networks and systems. Integrating APIs into our systems makes it equally important to consider API testing. Our APIs must be carefully and completely evaluated on various quality factors. For this, a variety of best API testing tools are available in the market. What is API testing? API testing entails many components and goes beyond running a few tests. An API or application programming interface is examined during the API testing. This is conducted to ensure that your API satisfies usability, privacy, efficiency, and dependability requirements. These tests are conducted as a component of the testing process or on the API itself. Business logic analysis and the security of software and information