Which method is commonly used in visual testing?

The method commonly used in visual testing is snapshot comparison. This technique involves capturing images of the user interface at different stages of development and comparing them against baseline images to identify visual discrepancies. This approach is particularly effective for detecting unintended changes in the visual appearance of applications, such as layout issues, color changes, or missing elements, which can affect user experience.

Snapshot comparison leverages automation tools that facilitate the comparison process, making it easier to manage and maintain graphical integrity throughout the development lifecycle. By identifying visual differences automatically, this method helps ensure that the application's design remains consistent with the intended look and feel.

In contrast, unit testing primarily focuses on individual components of the code rather than their visual representation, while regression testing is concerned with verifying that changes in code haven’t disrupted existing functionality. Load testing is aimed at assessing system performance under various conditions rather than visual aspects. Therefore, snapshot comparison stands out as the most relevant method in the context of visual testing.