Visual Testing - Overview

Visual Testing, also called visual UI testing, is the answer to many prevailing problems. It verifies if the software user interface (UI) appears accurately to all users. Visual Testing ensures that each element on a web page or a web/mobile application appears in the right shape, size, and position.

For example, On an e-commerce website, a customer is trying to make a purchase. A Customer looks for a shirt that they like, but is not able to find the “Add to Cart” button on the mobile browser, so they drop the idea and move on. However, when investigated, it was found that the button was hidden by a text box because of the mobile device’s space constraint. Looking back this error was not detected in the testing phase, but later became a significant hurdle in the whole user experience journey.

This was a classic example of where Visual Testing comes to play. Scenarios like these can be resolved quickly and prevented with running a visual test to check for any visual regressions.

Why Visual testing?

We perform visual testing because visual errors occur more frequently than we might realize. Visual testing requires the tester to consider how the application looks in addition to how it works. Oftentimes, the UI of an application can pass a functional test, while design elements that are visually defective can go under the radar.

Performing visual testing enables us to see if each element on a web page, web/mobile app appears in the right shape, size, and position. It also checks if these elements appear and function perfectly on a variety of devices and browsers. In other words, visual testing factors in multiple environments, screen sizes, OSs, and other variables that affect the applications UI.

Limitations

• Both Base Image and Differentiating format should be in the same format (supported formats - PNG, JPG)
• Both Base Image and Differentiating Image resolutions have to be the same. The User will also need to ensure that the resolution of the device you perfom the test on has the same resolution as well.
• Image resolution should be same as the device resolution

Importance Of Visual Validation Testing

No matter how accurately your application functions, it won’t be of any use to the customer unless it provides an astounding user interface and user experience.

These days, we not only talk about UI (User Interface), but we also focus a lot on UX (user experience). When we talk about delivering superior user experience, visual testing becomes all the more important as you would need to consider the visual appeal of the app design so that your users can easily understand and navigate through the app without any hassle.

Some areas where visual validation testing is highly recommended are -

• Mobile Apps
• Mobile Web/Responsive Web
• Marketing websites
• Consumer systems like airlines, travel, banking, etc.

You can perform the Visual Testing using two methods -

• Method 1 - Through API
• Method 2 - By using pre-build command