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UI testing: A simple (but complete) guide

Written by Katalon Team | Jul 20, 2023 3:20:00 AM

UI testing is the practice of validating an application's user interface (UI), the part that is visible to and interacted with by end users, to ensure that it looks, behaves, and responds as intended.

It encompasses all visual and interactive components, ensuring they meet design specifications, function correctly, and offer a smooth, intuitive experience. Effective UI testing verifies that buttons, forms, layouts, and dynamic elements not only work properly but also remain consistent across different browsers, screen sizes, and devices.

Benefits of UI Testing

  1. Better User Experience: Fixes issues like broken buttons and incorrect links to avoid user confusion.
  2. Higher Product Quality: Ensures the app looks good and works smoothly.
  3. Consistent Design & Branding: Keeps the UI aligned with brand guidelines.
  4. Improved Usability & Accessibility: Makes the app easy to use for all, including people with disabilities.

📚 Read More : Accessibility Testing: A Detailed Guide

UI Testing vs. GUI Testing

UI testing is a broader term compared to GUI (Graphical User Interface) testing.

 

  • UI is all of the ways that a person interacts with a machine (including graphical and non-graphical ways).
  • GUI only counts the ways that involve the use of graphics on displays. 

From this perspective, testing how well a keyboard interacts with a website would be considered UI testing, but not GUI testing.

UI Testing Checklist

  • Layout & Design: UI tests help verify that all layout elements, including alignment, fonts, colors, and spacing, follow the design system.

  • Navigation: UI testing ensures that menus, buttons, and links are functioning correctly and navigate to the appropriate pages.

  • Forms & Inputs: UI tests validate the behavior of text fields, dropdowns, checkboxes, and confirm that input validation works as expected.

  • Responsiveness: UI testing checks how the interface adapts to different screen sizes and devices, maintaining usability across breakpoints.

  • Cross-Browser Compatibility: UI tests are used to confirm that the application performs consistently on major browsers like Chrome, Firefox, Safari, and Edge.

  • Buttons & Links: UI testing confirms that all buttons and links are interactive, responsive, and visually consistent with the design.

  • Images & Icons: UI tests identify broken images and ensure proper alt text is included for accessibility compliance.

  • Error Messages & Notifications: UI testing helps validate that error states and notifications are clear, accurate, and triggered at the right time.

  • Accessibility: UI tests support checking keyboard navigation, screen reader compatibility, ARIA attributes, and color contrast for inclusivity.

  • Performance: UI testing contributes to monitoring page load times, interaction delays, and overall application responsiveness.

UI Testing Challenges

  • Frequent UI Changes: Frequent updates to the user interface can break existing tests, which requires continuous maintenance and adjustment.

  • Cross-Browser & Device Compatibility: UI tests must ensure that the application performs correctly across various screen sizes and different web browsers.

  • Flaky Tests: Minor delays, animations, or timing issues can cause UI tests to produce inconsistent and unreliable results.

  • Accessibility Testing Complexity: Ensuring that the application meets accessibility standards demands additional testing effort and careful validation.

  • Automation Difficulties: Some dynamic or visually complex UI elements are difficult to test accurately using automated testing tools.

Types Of UI Testing

There are several ways we can categorize our UI testing activities:
 

Category

Activity

Functional Testing

Test the functionality of UI elements to see if they work as expected.

Visual Testing

Test the visual aspects of the UI, including:

  • Overall visual design and aesthetics
  • Layout and alignment of UI elements
  • Color schemes and consistency
  • Typography and font styles
  • Graphical elements and icons
  • UI component styling (buttons, input fields, checkboxes, etc.)
  • Visual responsiveness across different screen sizes and resolutions
  • Visual consistency across different browsers and platforms

Usability Testing

Manually interact with the UI to see how easy-to-use and intuitive it is from the end-use perspective. Aspects to consider include:

  • Ease of navigation
  • Clarity of instructions
  • Areas of optimization to help users accomplish their desired task faster

Accessibility Testing

Test to see how accessible the UI is to users with disabilities, including:

  • Keyboard accessibility
  • Screen reader compatibility
  • Color contrast
  • Alt text for non-text elements
  • Image and video formats

Cross-browser Testing

See how the UI is rendered across different environments, including:

  • Browsers (Chrome, Firefox, Safari, etc.)
  • Operating System (Windows, macOS, iOS, Android)

These environments change the UI in their:

  • Layout (due to screen size differences)
  • Color
  • Functionality (certain features work on one browser but not on another)

Manual UI Testing vs Automated UI Testing

Similar to any other types of testing, there are 2 major ways to do UI testing: automated testing and manual testing.


1. Automated UI Testing

Automated UI testing uses test scripts to interact with the UI. Testers run the scripts and analyze the results.

Benefits:

  • Runs tests quickly, saving time and effort.
  • Eliminates human error with precise execution.
  • Increases test coverage for more scenarios and UI components.
  • Supports regression testing to catch issues after updates.
  • Scales easily for complex and multi-platform testing.

Challenges:

  • Requires time and expertise to set up automation frameworks or tools.
  • Dynamic UI elements (e.g., shopping cart icons) can be tricky to test.
  • Test scripts need frequent updates when the UI changes.
  • Can miss subtle UI issues that require human judgment.

📚 Read More: Top 15+ Best Automation Testing Tools For UI Testing

2. Manual UI Testing

Manual UI testing is done by a human tester without automation tools. They plan, test, and document results manually, sometimes using tools like Google Sheets for tracking.

Benefits:

  • Flexible, adapts well to dynamic UI changes.
  • Human intuition helps catch subtle bugs missed by automation.

Challenges:

  • Time-consuming, especially for complex tests.
  • Prone to human error and inconsistent results.
  • Hard to scale, requiring more testers as projects grow.

Read More: From Manual To Automation Testing: 5 Essential Steps

Popular UI Testing Tools And Frameworks

1. Selenium - Open-source Automation Testing Framework


 

Selenium is a well-known open-source framework used for automating UI tests. It is widely used in the testing industry and can automate test scripts on different operating systems like Linux, Mac, and Windows, as well as various browsers such as Chrome, Firefox, Internet Explorer, and Headless Browsers.

 

Key features:

  • Supported programming languages: Java, C#, Python, JavaScript, Ruby, PHP, and more.
  • Supported browsers: Chrome, Firefox, IE, Microsoft Edge, Opera, Safari, and more.
  • Parallel and cross-browser executions allow for testing on local or remote machines, speeding up execution and expanding test coverage.
  • Integrates with leading CI/CD tools and other testing frameworks.


2. Katalon - AI-powered Visual Testing Tool

Katalon is an excellent software quality management platform that can make your UI testing a breeze.

With Katalon, QA teams can:

  • Unify all testing activities (test planning, test authoring, test execution, test artifact management, to test analytics and reporting) in one platform
  • Create automated UI tests for web, mobile, API and execute across a wide range of environment
  • Receive AI-powered test case recommendations, generate synthetic test data, create test cases from plain language input, and auto-maintain flaky tests

Key Features:

  • One central platform for both functional and visual testing
  • AI-powered features like Layout Comparison and Text-to-text Comparison
  • On-cloud test environments available for a wide variety devices
  • Self-healing capabilities to automatically maintain automated visual tests
  • Easy integration with CI/CD pipelines such as Jenkins, GitLab, and Bamboo

Download Katalon and Start UI Testing

3. Cypress

Cypress is an automation solution specifically designed for web testing. It focuses on supporting JavaScript frameworks. With its unique architecture, Cypress can run alongside your application in a browser, giving direct access to elements and faster execution during testing.
 

Key features:

  • Easily captures test snapshots.
  • Efficient debugging and step-by-step test execution using popular developer tools.
  • Controls network traffic, timings, server responses, and function behavior.
  • Accesses a dashboard service to enhance test performance.
  • Offers real-time support.

📚 Read More: Katalon vs Cypress: A Detailed Comparison

UI Testing Best Practices

  • Define what UI aspects and functionalities need testing.
  • Cover functionality, usability, responsiveness, accessibility, and compatibility.
  • Test both positive and negative scenarios for thorough coverage.
  • Use consistent test data to check different cases and edge conditions.
  • Automate repetitive tests to save time and improve efficiency.
  • Perform cross-browser and cross-device testing to ensure a consistent user experience.

 

Start Testing With Katalon
 
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