Cross Browser Testing Checklist: Ensuring Comprehensive Coverage

Cross Browser Testing

Ensuring the compatibility of your web application across different browsers is crucial, as you cannot predict which browser your users will choose to access your website.

While you may design an exceptional app that appears flawless on Chrome, it might not hold for Internet Explorer (though it’s discontinued) or Safari browser online. Cross browser testing serves as a preventive measure, guaranteeing the proper functionality of your app across all major browsers. This proactive approach helps in retaining your customers and ensuring their satisfaction.

When is cross-browser testing necessary?

The timing for cross-browser testing may vary based on your role and workflow:

  • During Development: Developers, as part of Continuous Integration pipelines, conduct cross-browser tests before deploying changes to the production environment. This practice ensures that new features are compatible across different browsers.
  • In Staging/Pre-Release: QA teams perform cross-browser testing for each Release Candidate in the staging or pre-release phase. This is a crucial step to verify that the most recent version of the website does not exhibit any browser compatibility issues before it goes live.

Performing Cross-Browser Testing: Methods and Tools

Cross-browser testing, also known as website browser testing, can be executed through two primary approaches:

Manual Cross-Browser Testing:

Teams can opt for manual cross-browser testing, where they observe functional changes on different web clients, or manually test scripts on various clients. While suitable for smaller websites and applications, the extensive human interaction required for precision, particularly thorough testing, can be impractical. To manually test a website, multiple browsers and operating systems must be installed on different desktops and mobile devices.

The same test cases are then manually executed in each chosen environment. This manual process is time-consuming and exhaustive for testers, leading to a considerable testing duration. Moreover, manual testing in diverse scenarios becomes impractical. Consequently, the need for cross-browser testing automation arises to expedite testing activities.

Automated Cross-Browser Testing:

Imagine manually testing a website across multiple browsers, assessing every element and page—a daunting and impractical task given the multitude of browsers, operating systems, and devices on the market. Automation becomes indispensable for organizations aiming for uniform application performance across all supported devices. Automation tools for cross-browser testing play a pivotal role in addressing this challenge.

These tools offer various features, including access to thousands of real test environments, testing on real-time devices with different resolutions and configurations, and support for visual, functional, and regression testing. Additionally, they enable parallel test execution, ensuring faster completion, and provide integration with Continuous Integration/Continuous Deployment (CI/CD) pipelines.

Test reports generated by these tools include screenshots, logs, and, in some cases, video recordings of the testing process, offering comprehensive insights for reference when needed.

In this context, LambdaTest emerges as an AI-powered test orchestration and execution platform for cross-browser testing, streamlining the testing process and providing features like real test environment accessibility, support for various testing types, parallel test execution, and detailed test reports. LambdaTest is an AI-powered cloud-based testing platform that enables users to perform testing across 3000 browsers, operating systems, and real devices.

Pre-Testing Considerations for Cross-Browser Testing

Making decisions in the pre-testing phase is crucial for effective cross-browser testing.

Here are key aspects to consider:

Choose Critical Scenarios:

Prioritize testing essential scenarios first based on business criticality of functionality and UI usage before addressing the remaining test cases.

Choose the Environments and Compare:

The testing team executes test cases on different platforms and browser combinations to ensure functionality and check compatibility across browsers. Any discrepancies lead to defect reports raised by the QA team, and the development team addresses them.

Operating System:

Identify the primary operating systems your users will use, such as Windows, Android, iOS, macOS, etc.


Determine the platforms your users will access your application on, including desktops, mobiles, tablets, smart TVs, laptops, etc.

Scenarios for Devices:

  • Compatibility with tablets
  • Functionality on mobile devices
  • Responsiveness to specific resolutions
  • Availability on Windows platform
  • Accessibility on Apple iOS
  • Supported device platforms

Browser (Mobile and Desktop):

Decide on browsers crucial for cross-browser testing based on user preferences and analytics. Tools like Testsigma enable parallel testing, expediting the testing process.

Scenarios for Browsers:

  • Website visibility in the browser
  • Visibility of elements (buttons, forms, menus)
  • Clickability of elements
  • Content visibility on all devices
  • Specific browser version requirements
  • Page loading time in the browser

CSS Compatibility:

CSS is pivotal in cross-browser testing, influencing a website’s performance. Consider scenarios such as:

  • CSS version and browser support
  • CSS rendering engine
  • Presence of CSS errors
  • Effect of CSS minification on rendering
  • Responsive layout code in CSS
  • Calls to external image and font sources
  • CSS size impact on page speed


Assess websites under various network conditions to construct relevant test cases.

Network-related Questions:

  • Webpage loading on a slow connection
  • Website functionality on a slow connection
  • Missing critical elements during rendering on an idle connection
  • Influence of Content Delivery Network (CDN) on webpage rendering
  • Impact of ISP speed on page rendering across browsers
  • Browser responsiveness to sluggish connections

Selecting Emulators/Simulators and Devices:

Clearly understand the need for emulators, simulators, and real devices for cross-browser testing when choosing an appropriate automation testing tool.

Cross-Browser Testing Automation Tools:

Consider factors such as access to diverse environments, parallel test execution, maximum coverage of test scenarios, and reusability of test cases when selecting a cross-browser testing tool.

In conclusion, a Cross Browser Compatibility Testing Checklist can help identify flaws in your website, ensuring its resilience across diverse environments.

Starting with Cross-Browser Testing: A Comprehensive Guide

Handle Older and Rarely Used Browsers:

Evaluate compatibility for older and less popular browsers, even if their usage is minimal. Some users may still rely on outdated browsers that lack support for JS or CSS features. Redirect users, or create a basic version of the application for these browsers. Consider writing a separate stylesheet for browsers like older versions of Internet Explorer (IE).

Test Early:

Initiate unit testing as each page is developed. Early testing helps identify and address defects promptly. Once the application is ready, conduct comprehensive functional and visual testing.

Handle Non-Browser Dependent Bugs:

Some bugs are consistent across browsers and are not browser-dependent, particularly CSS-related issues. Testing such bugs on every browser may be optional, saving time. Techniques to test style-related bugs include resizing the browser, testing with CSS off, testing with JavaScript off, testing with both CSS and JavaScript off, and zooming in and out.

Prioritize Browsers:

Prioritize browsers based on their usage and potential risk:

  • Low risk: Top 4-5 widely used browsers (e.g., Chrome, Firefox, Safari)
  • Medium risk: Browsers with moderate usage
  • High risk: Rarely used or outdated browsers

Test high-risk browsers first by varying resolutions and screen sizes. Next, test low-risk browsers on different devices. Finally, test a few medium-risk browsers. Address and fix issues encountered through iterative testing.

Future Expansion:

Consider future expansion and potential increases in the user base during cross-browser testing activities. Anticipate changes in user behavior, such as the significant growth of mobile users, and incorporate them into testing strategies.

Features Analyzed in a Web Browser Test:

When limited time is available for compatibility testing, create a test specification document outlining essential features, browsers/versions/platforms to test, test scenarios, schedules, and budgets. Ensure coverage in the following areas:

  • General browser compatibility (CSS, DOCTYPE, SSL, HTML, XHTML)
  • Functionality, including form fields, cookie functionality, and touch input responsiveness
  • Design adherence to criteria set by the design team
  • Responsiveness, ensuring fluid design adaptation to various screen sizes and orientations
  • Utilize a browser compatibility testing checklist to avoid overlooking crucial aspects, ensuring the proper functioning of the website for all users.


Cross-browser testing is an exhaustive process and can pose significant challenges when attempted manually. Therefore, adopting test automation becomes essential for achieving thorough cross-browser compatibility testing. Nevertheless, creating and maintaining test automation scripts, managing testing infrastructure, test beds, and suites, as well as keeping scripts updated and addressing intricate testing scenarios, consumes valuable developer time.