7 Cross Browser Compatibility Testing Issues to Keep your Application Functional

How many times do you see a different appearance of the browser on your desktop and on your mobile? Multiple times, maybe. And every time you view the browser on a separate device, you might find one device offers more extensive features than the other.

This often happens when using the browser on a desktop compared to when viewing the browser on a mobile device. Here’s the thing: different users use different browsers, and every browser comes with a different version. Supporting them becomes challenging with more devices, and operating systems. Developers cannot assume a website to look great on every browser. They need to optimize the browser and its different versions for the websites to be compatible with cross browser testing automation. To ensure this, let’s understand the common browser testing issues developers and QA specialists must know.

1.Use CSS resets

Browsers come with their own set of CSS rules. These rules vary from one another, resulting in a particular style that may appear different in other browsers. To resolve this issue, use CSS resets to give instructions to the browser to remove styling to default CSS. Some examples of the CSS reset style sheets include:

  • Github based Normalise.css
  • HTML 5 Reset
  • Eric Meyer’s Reset CSS

Using any of these resets on your page, you can ensure proper CSS resets. This example can show you the way to use Normalise.css to fix the browser compatibility issue:

<link rel= “stylesheet” href =”assets /style.normalise.css”>

2.Validate HTML and CSS tag

Every browser reads, interprets, and handles its CSS code differently. While writing the code, there might be chances the developer may eliminate the closing tag or the semicolon, which impacts the entire syntax resulting in validation compatibility issues. Or, there might be chances the web designer is not validating the CSS code using an HTML/ CSS validator. To eliminate the validation compatibility issue, adopt the following practices when writing the CSS code:

  • Write well-aligned code
  • Insert comments wherever required
  • Indentation and matching the opening-closing braces

Also, use tools such as W3C HTML validator, Jigsaw CSS validator, JS Formatter for HTML, CSS & JS Lint for code validation.

3.Maintain layout compatibility

When the developer applies CSS resets and removes the default design in the browser, it causes layout compatibility issues. This happens because of lack of support for some layouts and non-responsive designs on specific browsers or their variations. For effective performance, you need a responsive application that works on all devices, platforms, browsers, and different versions.

To resolve this compatibility issue, use:

  • CSS Multi-Column Layouts: It maintains the proper layout of multiple column content according to the container’s layout.
  • CSS Flexbox and Grid: It lays out child elements based on their content and space for rendering.
  • HTML Viewport Metatag: It ensures the content is appropriately distributed across the mobile screen.

4.Check Javascript issues

 When DevOps use non-supportive features in older browsers, inappropriate DOCTYPE, or wrong browser sniffing code, they are likely to face browser compatibility issues. Some of these JavaScript related browser issues include:
Aligning ECMS Script Versions for different browsers

  • ECMA Script Version 6 supported only using polyfills
  • No JavaScript Native Support available
  • Code bloat caused by compiler
  • JS containing multiple modules and packages leading to slow down of application

Even though DevOps might find solving these browser compatibility issues with JavaScript problematic, there are a few ways to do it:

  • Use JavaScript Library to ensure the library supports browsers and features of the application
  • Use Javascript Transpiling to convert ECSMS/ ES6 Script-based code into code that can run on older browsers

5.Check DOCTYPE tag

The DOCTYPE keywords help define the rules to be used in the code. Using the DOCTYPE tag allows the web browser to recognize the HTML version used on the website and prevent it from being non-functional.

For example:

Some older versions of Internet Explorer check for the DOCTYPE tag at the beginning of the code. If the browser cannot find the tag, the application is not rendered correctly.

Now, let’s understand the working of the web browser in 3 different modes:

Full Standard Mode: In this mode, the browser implements strict checks in the standard full mode. The browser then checks for errors using W3C specifications.

Almost Standard Mode: In this mode, the browser implements fewer quirks.

Quirk Mode: This mode provides backward compatibility to old browsers. However, in this mode, browsers do not perform error checks. The browser moves to quirk mode when a code misses the DOCTYPE tag. It then stops checking the errors and behaves in a non-standard manner making it essential to add the DOCTYPE tag at the beginning of the code.

6.Test on real devices

You can test applications in a virtual environment however, real devices such as mobiles, tablets, and laptops are the accurate platform for functional cross device testing. To set up a real device manually, you will need tools to help you execute cross browser testing manually or let you automate and run them.

7.Check for outdated browser

When the used version of the browser is not known, the browser will break. Even the older versions of browsers like Internet Explorer, Firefox, Mozilla, and Google Chrome are covered in the category of outdated browsers. Such browsers use older browser detection tips.

With the change in technologies, CSS continues to evolve. And when your CSS code does not run on a modern browser, it means your browser is outdated and cannot handle modern browsers. Usually, this browser compatibility testing issue occurs due to obsolete Java scripts.

To solve browser compatibility testing issues, use the Modernizer library. This library lists down all the browser’s features and streamlines the experience.


Cross browser testing is directly proportional to an enhanced user experience for your applications. By understanding the above-mentioned 7 cross browsing compatibility issues, developers can keep a strict check and know what to do when any of these issues arise. However, to eliminate these issues, an ideal way is to conduct cross browser testing.