Provided is a system and method capable of automatically testing a website or application for an error in a user interface without human intervention. As an example, in a system for testing an error in a user interface of an application or website, a user interface system that includes a testable action recognizer that obtains a screenshot of a screen of the application or website, manages a layout and a test action based on user interface (UI) configuration and text recognition information from the screenshot, and a test action generator that receives the layout, selects a test scenario corresponding the layout, and performs a test action according to the test scenario, and in which the testable action recognizer manages whether or not a test is progressed for each screen layout according to the test scenario, is disclosed.