Compared with graphical user interface (GUI) testing, application programming interface (API) testing provides several key advantages, each of which can improve the coverage of your test cycle, conserve resources, and result in faster, more efficient releases. Based on your project timeline, integration requirements, and desired functionality, API testing is usually a worthwhile approach when testing your application in-house or with an offshore QA team. Four key advantages of API testing include:
- Test for Core Functionality
The first major advantage of API testing is access to the application without a user interface. Testing the core, code-level functionality of the application provides an early evaluation of its overall build strength before running GUI tests. This helps expose the small errors that can fester and become larger problems during GUI testing. Core access also enables testing in tandem with development, fostering communication and improved collaboration between both teams. This is especially advantageous if you are performing your API testing with an offshore QA team.
- Time Effective
API testing is far less time consuming than functional GUI testing. In GUI testing, webpage elements must be polled, which slows the testing process down immensely. To get an idea of the amount of time APIs can save when testing the core functionality of your application, consider the following real life example:
3,000 API tests in 50 minutes (in parallel execution)
3,000 GUI tests in 30 hours (in parallel execution)
Though this statistic is an average calculated by our team of engineers, you can expect comparable time savings if you use an API for a similar test routine. API test automation requires less code and thus provides better, faster test coverage than automated GUI tests. The end result of faster testing is a reduced overall testing cost.
In an API test, data is exchanged using XML or JSON. These transfer modes are completely language-independent, allowing you to select any core language when pursuing automated testing services for your application.
- Easy Integration with GUI
With API testing, highly integrable tests are possible. This is especially beneficial if you plan to perform functional GUI tests following your API testing. For example, easy integration would allow for the creation of new users within the application prior to the start of a GUI test.
Looking for additional resources as you prepare for API testing? Download our free whitepaper to learn more about the step-by-step process and benefits associated with this approach.