Compatibility Testing

software quality assurance engineer

This article provides insights into one of the important non-functional testing types that usually gets overlooked during the software development lifecycle. and how we at Q-Pros plan, design and execute compatibility testing across different platforms without impacting the launch timeline and burdening the budget.

Compatibility testing is a type of non-functional testing that helps in checking the web or mobile applications on various computing platforms being used by end-users. It validates that an application works as expected when accessed through:

  • Different Browser-OS combinations (i.e. on popular browsers like Firefox, Chrome, Edge, Safari—on any of the popular operating systems like Windows, macOS, iOS, and Android).
  • Different devices (i.e. users can view and interact with the application on popular devices, smartphones, tablets, desktops, laptops, etc).

Therefore, the objective of compatibility testing is to release web or mobile applications that deliver a uniform user experience on a diverse, ever-growing range of browsers, operating systems, and devices.

Since compatibility testing is a very wide topic and it would be a long article to cover it all here, this article is meant to focus on compatibility testing for websites and web applications.

Why is Cross-Browser Testing Important?

If a website or web application works well on one browser, that doesn’t imply that it will work well on the other browsers too. Thus, this testing helps ensure that it runs on different browsers without any errors.

To identify what breaks on which browser and to fix the website accordingly we need to perform this testing. If a browser is not at all supported, then the users can easily be informed about it to manage their expectations from the outset.

Cross Browser Testing

What is the impact of ignoring Cross-Browser Testing?

Imagine that a user is trying to access a website on a specific browser OS but the page does not display correctly. The user is likely going to do one of two things. First, assume that the site has an issue and leave to return later, or second assume that the site is broken and leave to find an alternative.


Browser vendors follow Open Web Standards, but they have their own interpretations of them. Since they each render HTML, CSS, and JavaScript in unique ways, thoroughly debugging the website’s source code is not enough to ensure that your website will look and behave as intended on different browsers (or different versions).

Cross-browser testing helps with that by pinpointing browser-specific compatibility errors so developers can debug them quickly. It helps ensure that all target audiences can access the website without issues.

How to best select which browsers to test?

The combination number of browsers, devices, and operating systems out there makes it impossible to build for and test every combination that may exist. Hence, we at Quality Professionals leverage market-leading tools (from vendors like SmartBear, Google, Microsoft, etc.) to automate the test where it gets done once and replicated across all required combinations.

But for manual compatibility testing, it would be more realistic to focus the effort on maximizing the web application reach within the market of the targeted audience. To do this, we first work with our clients to lock down the most critical browsers and versions:

    • Based on market share (popularity) in specific countries or regions.
    • Based on the traffic stats of the web application itself. We usually work with the digital or marketing team that handles the application or website.

Our test engineers take these stats and accordingly prioritize the effort so we start with common ones first. We also test responsive to ensure we mimic users accessing from smart devices.