Internet Explorer Online: Advanced Testing Approaches for Legacy Support

A serious problem for several organizations is that the systems of the organizations were developed decades ago. This results in using technologies in the system that were created long ago. 

These organizations are now in a situation where they either have to modify their software or replace it. One such example is Internet Explorer Online, developed by Microsoft. It is a retired series of graphical web browsers used in the Windows line of the operating system.

The challenge that arises for the testers is how they can assist these organizations and help them in testing their applications. The usage of advanced testing approaches with the help of Internet Explorer Online can be used by testers to overcome these challenges.

In this article, we will discuss Internet Explorer, testing legacy systems, how to identify a legacy system, challenges faced by developers in Internet Explorer online, and, its advanced testing approaches. 

What is Internet Explorer Online?

Internet Explorer testing assesses a web application or website to ensure its compatibility, appearance, and functionality in the “Internet Explorer Online” designed by Microsoft. 

Even though Internet Explorer is not actively developed anymore, it is still used by some organizations. So, it is essential to test on Internet Explorer to provide the user with a smooth and harmonious user experience. It is important to test on IE as it has different features, compatibility issues, and rendering behavior as compared to other browsers.

But to test the tester needs to verify if the application or website is on Internet Explorer. It can be verified by if the browser:

  • Remains user-friendly   
  • Functions correctly                                    
  • Displays as intended                          

Challenges faced by developers in Internet Explorer Online

Due to its quirks, legacy decisions, inconsistent behavior, and slow adoption of new web standards, Internet Explorer has presented several challenges to the testers throughout its existence. Depending on the versions of IE the challenges varied.

Mentioned  below are some of the main issues faced by developers while using Internet Explorer:

  • CSS compatibility issues

IE has often faced several challenges in adopting the latest standard of CSS. So to ensure consistent styling developers had to use fallbacks or browser-specific hacks.

  • PNG transparency problems
    Alpha transparency in PNG images correctly was not supported by IE 6.
  • Box model bugs

The CSS box model was interpreted by IE6 differently as compared to other browsers. As a result, layouts often appeared differently in IE as compared to browsers like Chrome or Mozilla Firefox.

  • Slow adoptions of HTML5

IE lagged heavily while other browsers quickly adopted HTML5.

It forced developers to use polyfills or any other alternative method to achieve the desired functionality.

  •  JavaScript inconsistencies

JavaScript execution had inconsistencies between IE and other browsers. This resulted in the script falling or behaving unpredictably.

  • Lack of modern Developer tools

There was a lack of modern developer tools which made performance and debugging testing more challenging as compared to Firefox or Chrome.

  • Inconsistent DOM

There were inconsistencies in the Document Object Model (DOM) in IE when compared to other browsers. It led to challenges in dynamic content manipulation. 

  • Performance issues

Concerning JavaScript execution and rendering IE often had performance compared to Firefox and Chrome.

  •  Security vulnerabilities

Earlier versions of IE, especially IE6 and IE7, had security vulnerabilities so it was criticized often. 

            The IE brand faced challenges after the rapid evolution of web standards.

            This led to Microsoft’s decision to develop Edge.

 Additionally, there are some challenges faced by the testers related to the features of  IE as well:

  • A different rendering engine is used by IE as compared to other browsers. This makes the tester’s website not display correctly in Internet Explorer. 
  • IE does not support all modern web standards so some features of the user’s website may need to be fixed in IE. 
  • Since IE is less up-to-the-minute with security patches than other browsers, the user’s website may be more vulnerable to security attacks.
  • IE is less optimized for modern websites than other browsers so the user’s website needs to be faster in IE.  

What is a legacy system?

Any outmoded computing system, hardware, or software that is still in use is called a legacy system. Software applications, computer hardware, programming languages, and file formats are included in legacy systems. Most of the legacy systems are still in use even if they are outmoded. Some organizations continue to use legacy systems as they are crucial to their daily functions and organizational needs.

Mentioned below are some reasons why an application, system, or any other technology becomes a legacy IT system:

  • Purchase of the system is no longer available and they are now not dependent on outdated technology to run and maintain.
  • Support, maintenance, and updates by application developers are no longer received by these systems.
  • IT professionals with largely, complex outmoded technology skill sets like COBOL, are required.
  • The repair of the system takes a long time.
  • These systems are overly exposed to security problems, and updating the system to meet cybersecurity standards is not possible. 
  • The maintenance of the system is too costly.  

How to identify a legacy system?

Some simple ways to identify legacy systems are mentioned below:

  • The application is very old but it is still in use.
  • The functioning, performance, security, features, and reliability of the system are not clear.
  • The system has an outdated underlying technology stack.
  • It does not have compatibility with modern technologies, services, computing environments, or platforms. 

Advanced testing approaches for legacy support using Internet Explorer Online 

Depending on the type, complexity, and state of the system testing the legacy system is a very essential part. However, these testing approaches need to have a few key changes.  Here are some best practices to be adopted while performing tests on legacy systems using Internet Explorer:

  • Implement testing within the CI/CD pipeline

The tester should implement CI/CD pipelines as it makes sure that new changes don’t break existing functionality. It also checks that automated tests are run on every check-in. CI helps organizations to deliver new features faster. 

  • Go big

Using Internet Explorer for legacy support, it is much better to look at the tests from a wider perspective and see a bigger picture. The tests for legacy systems must be performed on a large scale. 

  • Prepare the set of smoke tests

Internet Explorer online provides a set of smoke tests like snapshots of the application at a particular state. They let the testers see what needs testing and what doesn’t. They only test to get a general idea of how things work and not every possible scenario.

            A good smoke test is a must for legacy system testing.

  • Plan regression test

The main issue with the legacy system is the need for a regression test suite.

Internet Explorer Online provides a regression test suite that makes sure that any changes do not lead to unexpected behavior changes or any corruption. The tester can plan out a regression test for a better user experience. 

Utilizing LambdaTest in legacy testing with Internet Explorer  

Depending on the type, complexity, and state of the system, testing the legacy system might require some extra tools and steps. To start, the tester should choose a testing platform that supports the programming language and platform of the legacy system. For instance, if the user works with a Java-based legacy system, LambdaTest can be used. Using a cloud-based platform like Lambdatest helps testers improve application quality and reduces the cost and efforts of maintenance.

Lambdatest is an AI-powered test orchestration and execution platform used for manual and automated testing of web and mobile applications. This platform allows testers to perform real-time and automation testing by providing access to over 3000 environments, real mobile devices, and online browsers.

It is a cloud-based cross-browser testing platform that offers instant access to numerous browser versions and platforms. It also allows users to conduct cross-browser compatibility testing to ensure that the website renders the same across all browsers.  Along with this, it provides integrated debugging and testing features. Additionally to increase the efficiency of the application delivery and test cycles users can simultaneously perform parallel testing using the LambdaTest platform.


Advanced features for legacy support provide learning and improvement in many of the tester’s weak areas. The advanced features for legacy support using Internet Explorer Online mentioned above help the user to test legacy code easily by making it less painful and time-saving.

The advanced testing approaches provided by Internet Explorer Online will benefit the tester with higher-level tests. 

Hope this article provides you with the basic knowledge of legacy support and the advanced techniques or testing approaches that can be applied to legacy support.