Basics of Cross-Browser Testing

What is cross-browser testing?

Users should not be restricted to use an application on only one browser, so it’s crucial to test the application’s compatibility on multiple browsers. Some of the generally used browsers are Chrome, Safari, Firefox, Internet Explorer, etc.

Cross-Browser testing is used to verify that a website or a web application works correctly across different browsers. This testing method is applicable to both desktop and mobile browsers.

Why is it useful?

We may think that because HTML, CSS, and JavaScript have a detailed specification and all browsers are developed based on that specification, then the standards-compliant code should work on all major browsers without any adjustment. In reality, each browser interprets the information on the page in a different way and some of them might even lack the features that your website is trying to show. This results in your website looking sloppy or broken on some browsers.

Most of the big browser vendors (Google, Mozilla) are constantly implementing new features. While the application is in development, one can consult to check what is the browser support for a particular web standard. But even so, the only thing that will ensure that your web application looks and behaves correctly is to do cross-browser testing continuously.

What browsers should you test?

This is a very important decision to minimize the time and costs of your project. You shouldn’t spend time to test a browser that is not in your audience’s target. Most of the time, the decision on which browsers to test is made by the client and the business team and not by the tester.

The companies use traffic data to narrow down what browsers are commonly used by the selected audience. This data can come from a website like or from analytics recorded in production from a previous version of your web application.
The most commonly used desktop browsers are Google Chrome, Microsoft Edge, Firefox and Safari. On mobile we have Safari for iOS and Google Chrome and Firefox for Android.

How to perform Cross Browser Tests?

Cross Browser tests can be performed either manually or by using a test automation tool. The choice should be made according to the complexity of the project. If the project tested is a simple, static website, then manual testing is probably the best choice. If the project is more complex, with a longer life span and continuous development, then it’s worth investing time in automated testing.

  • Manual testing is by far the easiest method for cross-browser testing. The big disadvantage is that the process is time-consuming, so it is recommended to optimize it wisely. We recommend a more stable browser, like Chrome or Firefox because it comes with a range of built-in development tools which will make debugging easier. Manual testing is mostly used for visual components of the website or web application. After making sure that everything works accordingly, you can start testing the visual component in other targeted browsers. Always make sure that after fixing a bug in a specific browser, you test the affected component also in the rest of the browsers.

    For desktop browsers, manual testing is pretty simple. You install the browser on your machine and perform the required actions in your platform to verify the outcomes. Testing on mobile browsers is a bit more complicated. First of all, the application has to be tested for responsiveness. For this, you verify if the website automatically adapts to the current size of the device under test.

    Secondly, you have to test the web browsers. Each mobile web browser runs on a rendering engine. For example, on iOS, there is only one rendering engine (WebKit, the engine used by Safari and Chrome). For Android, there are several rendering engines on which browsers run, but the most commonly used are Chrome and Firefox. This means that in most cases, you can focus on the most important mobile browsers, Safari, Chrome and Firefox.

  • Automated testing is time-consuming when first creating the test scenarios, but in the long run, it’s very efficient. Basically, automated testing tools run the same set of test cases, on different browsers, multiple times. If the project is complex and has a long life span, you should run tests as often as possible, preferably after every commit. This ensures that bugs are caught early, making them easy to fix.

    Most of the testing tools do not integrate stable testing infrastructures, so developers spend a lot of time implementing and maintaining different testing technologies. Testerum comes integrated with most of the testing technologies, thus helping developers to focus on other important issues of the project.


Every type of test helps to improve the quality of the product. Cross-browser testing helps you ensure a good experience for the user on every platform. Automated and manual tests are both effective in different scenarios. Testerum offers the possibility of running both manual and automated tests from a friendly UI, without any programming skills needed. You can perform cross-browser tests from a tool integrated with Selenium and other technologies that can help you optimize the testing process. Find out more about us.