{"id":39297,"date":"2022-06-17T09:24:42","date_gmt":"2022-06-17T16:24:42","guid":{"rendered":"https:\/\/app14743.cloudwayssites.com\/?p=39297"},"modified":"2025-09-08T14:58:11","modified_gmt":"2025-09-08T18:58:11","slug":"visual-regression-testing","status":"publish","type":"post","link":"https:\/\/app14743.cloudwayssites.com\/blog\/visual-regression-testing\/","title":{"rendered":"What is Visual Regression Testing?"},"content":{"rendered":"\n

In this guide, you\u2019ll learn what visual regression testing is and why visual regression tests are important. We\u2019ll go through a use case with an example and talk about how to get started and choose the best tool for your needs.<\/em><\/p>\n\n\n\n

What is Visual Regression Testing?<\/h2>\n\n\n\n

Visual regression testing is a method of validating that changes made to an application do not negatively affect the visual appearance of the application\u2019s user interface (UI). By verifying that the layout and visual elements align with expectations, the goal of visual regression testing is to ensure the user experience is visually perfect.<\/p>\n\n\n\n

Visual regression testing is a kind of regression testing<\/a>. In regression testing, an application is tested to ensure that a new change to the code doesn\u2019t break existing functionality. Visual regression testing specifically focuses on verifying the appearance and the usability of the UI after a code change.<\/p>\n\n\n\n

In other words, visual regression testing (also called just visual testing<\/a> or UI testing) is focused on validating the appearance of all the visual elements a user interacts with or sees. These visual validations include the location, brightness, contrast<\/a> and color of buttons, menus, components, text and much more.<\/p>\n\n\n\n

Why is Visual Regression Testing Important?<\/h2>\n\n\n\n

Visual regression tests are important to prevent costly visual bugs from escaping into production. Failure to visually validate can severely compromise the user experience and in many cases lead directly to lost sales. This is because traditional functional testing<\/a> works by simply validating data input and output. This method of testing catches many bugs, but it can\u2019t discover visual bugs. Without visual testing these bugs are prone to slipping through even on an otherwise well tested application. <\/p>\n\n\n\n

As an example, here is a screenshot of a visual bug in production on the Southwest Airlines website:<\/p>\n\n\n

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\"Visual
Visual Bug on Southwest Airlines App<\/em><\/figcaption><\/figure><\/div>\n\n\n

This page would pass a typical suite of functional tests because all of the elements are present on the page and have loaded successfully. However, the visual bug is obvious. Not only that, but because the Terms and Conditions are inadvertently overlapping the button, the user literally cannot check out and complete their purchase. Visual regression testing would catch this kind of bug easily before it slipped into production.<\/p>\n\n\n\n

Visual testing can also enhance functional testing practices and make them more efficient. Because visual tests can \u201csee\u201d the elements on a page they do not have to rely on individual coded assertions using unique selectors to validate each element. In a traditional functional testing suite, these assertions are often time-consuming to create and maintain as the application changes. Visual testing greatly simplifies that process.<\/p>\n\n\n\n


How Do Visual Regression Tests Work?<\/h2>\n\n\n\n

At its core, visual regression testing works by capturing screenshots of the UI before a change is made and comparing it to a screenshot taken after. Differences are then highlighted for a test engineer to review. In practice, there are several different visual regression testing techniques available.<\/p>\n\n\n\n

Types of Visual Regression Testing<\/h3>\n\n\n\n