API Testing vs. UI Testing (2024)

FAQs

API Testing vs. UI Testing? ›

Conclusion. API testing and UI testing are complementary disciplines that jointly improve software quality and user experience. API testing focuses on validating application logic and backend functionality. UI testing replicates user workflows and verifies front end behavior.

UI testing is ideal for evaluating the end-user experience and ensuring that the graphical elements function as intended. On the other hand, API testing focuses on the underlying functionality and communication between different software components.

APIs tend to have more stable interfaces than UIs, which can change frequently with new designs or user interactions. Testing at the API level ensures that the core functionality works correctly, regardless of UI changes, leading to more reliable tests that do not need to be rewritten as often as UI tests.

Enter, application programming interfaces, or APIs. An API is very much the same thing as a UI, except that it is geared for consumption by software instead of humans. This is why APIs are often explained in the mainstream media as a technology that allows applications (software programs) to talk to one another.

Load Testing Tools.

Both load testing types use different tools in their process. UI load testing uses tools and techniques like Selenium, Load View, JMeter, or LoadRunner. API load testing is typically performed using a different toolset including Postman and SoapUI, although JMeter and Load View can also be used.

UI Testing, also known as GUI Testing is basically a mechanism meant to test the aspects of any software that a user will come into contact with. This usually means testing the visual elements to verify that they are functioning according to requirements – in terms of functionality and performance.

Unlike UI testing, which tests the look and feel of the application, API testing focuses on the business logic of the application. Also, this testing requires software to send calls to the API. The software will send requests to API, receive output, and compare the actual responses with the expected responses.

UI Designers do not need to code, but it is extremely beneficial if you have programming skills. Depending on the nature of the product, it's also not unusual for UI/UX design and development to be intertwined into a single process.

Automated testing requires you to use a testing tool, like SoapUI, while manual testing consists of writing your own code to test the API. API testing is one of the areas where automated testing is highly recommended, particularly in the world of DevOps, agile development, and continuous delivery cycles.

API testing can be implemented quickly – no GUI needed. Developers can easily shift left to get a head start, run tests, get instant feedback and resolve issues earlier on. Compared to UI tests, API tests take seconds, minutes maximum, to complete.

Is API testing easy? ›

They are test data management and verification. It is common that testing a few first APIs such as login, query some resources, etc. is quite simple. The testing task becomes more and more difficult to further APIs. Therefore, the API testing task is easy to be underestimated.

UI Testing: UI tests can be slower due to their involvement with the graphical elements and rendering of web pages. Maintenance: API Testing: API tests tend to be more stable and require less maintenance because they are less affected by changes in the user interface design.

API allows more flexibility when it comes to automation and innovation. GUI is less flexiballowle when it comes to automation and innovation. API allows your program to interact with servers. GUI allows users to interact with your program.

UI testing or user interface testing is a type of software testing that focuses on checking the appearance, functionality, and usability of different kinds of user interfaces, such as: Graphical user interface (GUI) Command line interface (CLI) Voice user interface (VUI)

GUIs typically comprise two main aspects: the user interface (UI), which is what the user sees, and the backend application programming interface (API), used to communicate with the underlying application or system.

Well, API testing is technically system integration testing (also known as interface testing). When you're carrying out integration testing, it's likely that the two systems require an API to be able to connect and communicate with one another. An API is a standardized way that systems interact with one another.

Interface can be thought of as a contract of service between two applications. This contract defines how the two communicate with each other using requests and responses. Their API documentation contains information on how developers are to structure those requests and responses.