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7 Common Cross Browser Compatibility Issues to Avoid

Shreya Bose, Technical Content Writer at BrowserStack -

Table of Contents

In this article, we will explore some of the most common reasons cross browser test cases can fail. Consider this a list of cross-browser compatibility issues that every developer/QA needs to be mindful of.

As it stands now, there are multiple browsers used by individuals across the world. Additionally, each browser has numerous versions which are also in use. Any website that wants to stand a chance at gaining a significant user base must be compatible across multiple browsers and browser versions.

This is where cross browser testing comes in. It has become an integral part of web development, to assure that a website is perfectly accessible to as many users as possible. With increasing fragmentation in browser availability and usage, cross browser testing is now a basic necessity in any web development project.

Now let’s dive into the issues that are most like to break cross-browser tests.

1. Lack of Testing on Real Devices

As the saying goes, nothing beats the real thing. No matter what your website is like, the best way to make it bug-free across multiple browsers and devices is to test on real browsers and devices, like real users. No virtual machine will ever be able to match the efficacy of native device features.

However, unless a tester has access to a personal device lab that is constantly updated with the newest devices and browser versions, real device testing can prove quite difficult and expensive. Platforms like BrowserStack address this need gap by providing instant access to a real device cloud with 2000+ device browser combinations. Simply test your website’s compatibility and responsiveness by logging in and selecting device-browser combinations of your choice. The user does not worry about updating or maintaining anything; they simply choose what they want to test on.

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2. HTML/ CSS Validation

Validation of HTML and CSS codes can pose major problems for developers during cross browser testing. This is to be expected since different browsers read and handle code in different ways.

It is entirely possible for developers to be hindered by an error as minute as not closing a tag. Certain browsers might auto-correct this, while others might not be able to display the feature that part of the code operates. Committing such as error might cause problems with, for example, Internet Explorer and not Chrome.

Solving this issue is fairly simple, thanks to code validating tools for HTML and CSS. Consider using W3C HTML validator and Jigsaw CSS validator.

3. Vendor-specific functions

Developers must take note that while creating features/functionalities, they have to use specific code in CSS, depending on which browser they are designing for.

Doing the above is integral to avoiding cross browser compatibility issues. The developer must add the function without the prefix as well, thus ensuring no error occurs in other browsers.

Some common prefixes to keep in mind are:

  • Safari and Chrome (-webkit)
  • Internet Explorer (-ms)
  • Mozilla Firefox (-moz)
  • Opera (-o)

4. DOCTYPE Error

This usually involves some kind of faulty rendering due to missing a basic line in the code. Browsers with outdated versions such as Internet Explorer 8.0 often check for the Doctype. If that is missing, the site is improperly rendered.

Doctype is checked because a browser operates in two modes – Strict Mode and Quirks Mode

  • In Strict Mode, the browser works with much stricter checks for code errors to make sure that the code is in accordance with W3C specifications.
  • Quirks Mode provides backward compatibility to older browser versions and do not perform such meticulous code error checks.

In case a webpage features a missing Doctype tag, the browser goes into Quirks Mode. Simultaneously, if the browser does not support HTML5, it won’t know which version to look for. Consequently, some of the tags will become unresponsive and the webpage will be displayed incorrectly.

It is simple enough to solve this. Just include a single line at the beginning of the codebase.


Do this, and be sure to receive a flawlessly rendered site in every browser.

5. Outdated Browser Detection

Since browsers contain technology to optimize output, this results in less consumption. At times, if an old browser is used, it is possible that Javascript has failed to detect the browser.

This common cross browser compatibility issue occurs due to obsolete Javascript.

Solution : However, one can remove the browser detection by using Modernizer, a set of “superfast tests” that enumerate all browser features, thus facilitating a seamless experience. Modernizer lets developers direct a site to focus on features rather than browsers.

6. Missing CSS Resets

By default, all browsers have a design layout that is applied to the website opened in them. If a website wants to utilize its own layout, it must override the default. Unless this is done, a website is rendered differently, depending on which browser is running it.

Solution : Resolving this issue simply requires the websites rendered to be reset to the same basics. Developers can use CSS reset style sheets for this purpose. By adding the style sheet, they ensure that layout design issues do not occur.

Commonly used reset style sheets include Eric Meyers CSS Reset, HTML5Reset, and the Github based Normalize.css.

7. Layout Compatibility

By applying CSS Resets, developers often remove the default design in browsers and apply their own. This can cause compatibility issues, either due to a non-responsive design or due to a lack of support for certain layouts on certain browsers/browser versions.

Solution : A common solution for this is to use floats that are supported by many browsers. Now, since a float is essentially a floating image inside a text box, it does offer certain limitations.

When working with modern layouts, it is better to use tools such as CSS grids and Flexbox. Since these tools are supported by most modern browsers, they are more effective for developers’ purposes.

6 Common Cross Browser Compatibility Testing Issues to avoid

By keeping the issues detailed above in mind, developers and testers are more likely to avoid them in the first place. Since cross browser testing is of such immense significance, mistakes in it can cause delays that are perfectly avoidable. By ensuring that these failures do not occur, browser compatibility testing can become a legitimate enabler, rather than a bottleneck in the software development process.

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