A client makes a request by asking for a resource the request then goes out and finds a server that can fill that request. This simple example is often referred to as a client/server relationship. Most headless testing consists of bypassing the UI and sending a request directly to an application's backend or service and receiving a response while validating the response to ensure things are working as we expect them to. While most functional testing involves testing a user interface like a web page or a dot net form, API testing involves bypassing a user interface and communicating directly with an application by making calls to its APIs.ĪPI testing allows you to test headless technologies like JMS HTTP, databases and Web services.ĪPI testing is sometimes called “headless” testing. What is an API?Īpplication Programming Interfaces (API) is a specification that acts as an interface for software components.

API tests, on the other hand, tend to be faster and run more reliably than GUI tests.īelow is a quick API testing tools comparison of open source options.īefore we take a closer look at the API testing tools, let’s make sure we’re all on the same page with what an API actually is. One downfall to UI tests is they are slow, making them a poor choice for letting developers know quickly if their code has broken the latest build or not. That why I create this list of the top 20 free API Testing Tools you should know.Īs we move towards more Agile shift-left software development processes like continuous integration and delivery, the need to quickly give test feedback to our developers is increasing. API testing tools are more important now than ever.

Api testing tools open source