Guide to Visual Regression Testing

April 9, 2023, 7:05 p.m.

Visual regression testing or VRT involves programmatically comparing similar images to discover any differences much like a human would.

Visual Regression Testing

The website of any business is critical to attracting potential customers. Customers form an opinion about a business based on their experience with its website. If a website has a poor user experience, customers are likely to form a negative image of the business and may not feel comfortable dealing with it. To prevent this from happening, businesses must ensure that their websites are visually appealing and user-friendly.

What is Visual Regression Testing?

Visual regression testing or VRT involves programmatically comparing similar images to discover any differences much like a human would. Additionally, VRT can be used to ensure any changes made to an application's code do not have a negative impact on its visual appearance and user interface. This testing focuses on visual interpretations such as contrast, brightness, location, text, and button color.

Significance of Visual Regression Testing

The significance of visual regression testing cannot be overstated. If visual defects persist on a website or application, a business may lose customers. Traditional testing methods may validate input and output data, but they may not catch visual bugs. Therefore, visual testing is essential to ensure that an application is bug-free.

Types of Visual Regression Testing

There are several different ways visual regression testing can be conducted, here are the most common:

Manual Visual Testing

One method is manual visual testing, where designers manually scan for visual defects. However, this process can be time-consuming and is prone to human error.

Comparison of Pixel

Another method is pixel comparison, which involves taking screenshots and comparing them pixel by pixel. This approach can sometimes produce irrelevant differences that do not impact the application's usability.

DOM-based Comparison

DOM-based comparison involves assessing the Document Object Model before and after changes are made to the application's code. However, this approach may produce false comparisons that need to be ignored, or they may change the user interface and require attention.

Visual AI Comparison

Visual AI comparison is another type of visual regression testing that allows an application to be viewed by a computer the same way a human would. This process is quick and accurate and does not produce false positives like DOM and pixel tests can.

Overall, visual regression testing is essential to ensure that customers have a pleasant experience with a business's website and applications. By utilizing the right testing methods, businesses can ensure that their applications are visually appealing, user-friendly, and bug-free. To maximize the effectiveness of visual regression testing, businesses should partner with an experienced provider of software testing services. This ensures that they get the most out of their investment in visual testing and can deliver the best possible experience to their customers.

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