Product Development

Why is Responsive Design Important and How to Test It?

9 min read time · last updated on
Speck Team

8.8 billion people step into the traffic of news, memes and blogs through the internet every day. While in the past, most people accessed the internet using desktop computers only, that is not the case today. Customer journey of a single user spans through multiple devices – phone, tablet, desktop, smartwatch, making it a challenge for companies to create frictionless digital experience across devices.

Depending on the location or even the phase of the day, a single user can visit the same platform or website through multiple devices in a single day. Creating amazing customer experience for a company or a brand starts with the clear vision of the customer journey complimented with responsive design. Today we are going to explore what responsive design is, why is it important and how to test it!

What is Responsive Design?

Responsive design is the approach to website design and development that suggests that the layout of the website should respond to the user’s environment including the platform, screen size and the orientation. The responsive web design concept provides a set of practices allowing web pages to alter the original layout and appearance to suit different resolutions, widths, devices etc.

In 2019 more than 50% of web traffic came from mobile devices. In order to create a successful user experience, every website today must be optimized and tested for different browsers, screen sizes, devices and orientations (landscape and portrait). Once a user reaches the mobile edition of a website, they should enjoy the same experience as on the desktop version.

Responsive Web Design Testing Checklist

Did you know that an average smartphone user spends about 4 hours and 30 minutes per day on their mobile devices? The chances are you are also reading this article on your smartphone. The simplest way to make sure that you are successfully doing responsive design testing is to follow a checklist. Which is why we have created a responsive web design testing checklist and have also included the most popular responsive test tools to help you get started!

Testing Navigation On Website

A navigation bar is used to access different parts of a website. As the device and screen size changes, the navigation bar should change with it too. In most cases, navigation bars are designed for desktop experience and are not fully visible on mobile devices.

One of the most common ways to solve a navigation challenge is to use hamburger menu icon for smaller screen sizes. Bear in mind that hamburger menus are becoming more sophisticated and can go beyond the triple bar icon into more customized and complex layouts.

Menu Icon Variations

Testing Fonts on Multiple Devices

Website designers use different fonts and font sizes to emphasize important messages and to make digital experience across different pages more visually attractive to users. These fonts sometimes may not be supported universally and might not be displayed properly across devices. If you don’t want the users to land on your page to see important marketing messages hidden between funny random characters and symbols, you should test the fonts on multiple devices before pushing your website live.

Font-face method supported across various browsers

Test For Small Screen Devices

The number of users accessing the internet through mobile devices is growing every day. Which is why more and more digital-first companies are adopting the mobile-first design approach while designing for mobile responsive websites.

If we for example take e-commerce website experience, a single customer shopping experience, from exploration to decision phase, can span through multiple devices. Therefore it is important that website design suits all device types such as mobile phones, laptops, tablets, etc.

Multi-Device Purchasing Path

Device-Browser Responsiveness Testing

Nowadays people use multiple devices, browsers and operating systems to access the website. To get a better overview over the devices and browsers customers use to visit a company’s website, analyze the website’s traffic using Google Analytics and consider the browsers and devices!

If you are using beta versions for testing, you can test the responsiveness of that version to prepare for the release. Make sure you check the responsiveness of your website on regular bases, for example every quarter, as new operating systems and devices are being introduced and old ones are being removed from the market.

Website Responsive Test for Speed

Regardless of how nice the website looks, the speed matters more than ever. Some of the research shows that nearly half of all the internet users expect a site to load within 2 seconds or less.

Responsive design reflects in website elements scaling up or down according to device. Having in mind that smaller devices such as mobile phones usually work on lower bandwidth, heavy elements such as images and videos are the main concern. To decrease the loading time on smaller devices, use alternate methods to render the same images and videos on these smaller devices.

In the picture below, you can see how the performance report looks on the GTMatrix for Speck website.

Performance report in the GTMatrix

Performance score is overall website score and the structure represents how well a page is built for optimal performance.

  • LCP measures how long it takes for the largest content element on your page to become visible within your visitors’ viewport. For a good user experience, aim for an LCP of 1.2 seconds or less
  • TBT tells you how much time is blocked by scripts during your page loading process. For a good user experience, aim for a TBT of 150 milliseconds or less
  • CLS indicates how much layout shift is experienced by visitors as page loads. Good user experience requires a CLS score of .1 or less. You can see this is the only criteria where the Speck website is not in the green.

Mobile Responsive Test for Alignments

Having multiple elements on the website can cause issues when trying to place them all on a smaller screen. Since they are quickly recognizable on mobile devices, element alignments for smaller screen sizes play a huge role in responsive web design testing.

Content Placement Testing

Bigger screens such as laptops have a larger surface and viewport, making it easier for users to locate every element. Also, distance between the screen and the user makes it easier to focus on every corner and more details than on the mobile device.

Mobile device screens are smaller and therefore, displaying everything as it is, might cause the device screen to look clogged and too congested. In the following image you can see the important areas of the mobile screen.

The important focussed areas of a mobile screen

Cross Browser Testing

Cross browser testing is a process of developing a website or web app to perform equally well across different browsers, browser versions, and operating systems. Providing hassle-free users experience includes testing and verifying that the website is cross browser compatible.

The list of browsers available and being used daily is almost endless, which is why cross browser testing includes manual and automated testing strategies. To learn more about cross browser compatibility testing, read here.

Test For Interactive Experience

One of the main goals of the responsive website testing checklist is that no matter what or how interactions occur, the interactive experience of a website or an app, does not change. Essentially, the website UI including buttons, CTA-s, navigation bar or footer elements, should try to integrate most through multiple models.

Lets see how this works on a real example:

Navigation model on the desktop and mobile device

In this image we can see the Speck website. On the left side we have a navigation model for the desktop version and on the right side you can see the navigation model using a hamburger icon to open the navigation list.

Test Website Popups Mobile-Friendliness

Most of the websites use popups to increase the website conversions. But, what might come handy can also be the flaw if not placed correctly.

Non-responsive website popups can get users easily annoyed and hurt the website’s reputation with search engines. Creating an impeccable user experience includes creating responsive popups that the user can close and continue with exploring the website.

With responsive design tests being performed, QA testers can ensure that the pop-ups that are displayed are responsive for multiple devices and shown properly no matter the screen size.

Responsiveness Website Testing Tools

Comprehensive testing approach will allow testers to check the website’s performance and behaviour on different devices, browsers and OS. Considering the checklist and all of the responsive web design tests to perform, it would be daunting to carry all these activities manually. Various test tools available cover a wide range of responsive website testing scenarios.

Inspect Tool in Chrome

The Inspect Tool in Chrome is widely used by developers for debugging, but it can also be used for testing screen sizes and viewports. It’s really simple to use, all that the testers need to do is right-click on any website and click “Inspect”. Once the inspect window opens, there is an icon for “devices” next to the button named “Elements”. When testers click on the “devices button”, their screen shows the website they are on at different breakpoints. In addition, testers can input a specific size or simply grab and drag the corner of the window to change the breakpoint manually.

Inspect tool in Chrome


Responsive website testing tools such as Screenfly allows QA testers to perform responsiveness tests for a variety of screen sizes and devices. Screenfly allows testers to add any custom screen size, and is also used to cover the testing the alignment, fonts and images.

Screenfly testing


Responsinator is used widely for testing the responsiveness of websites and its best quality is that it is easy to use! This tool is practical for quick checks in the most common devices, but it’s limited if you want to check all breakpoints.

Testing in the Responsinator

Am I Responsive

This is the simplest manual cross-browser testing tool that you will find and it might come in handy for quick testing purposes. All you have to do is to add the URL to the input field and click GO or press Enter. The tool shows four different apple devices for testing websites: desktop (resolution: 1.600 x 992 Pixel), laptop (1.280 x 802 Pixel), tablet (768 x 1.024 Pixel) and mobile (320 x 480 Pixel). One of the application’s advantages is that it allows different sizes to be directly compared. In addition, each screen is scrollable independently.

Testing in the Am I Responsive

Closing thoughts…

Every company’s website promotes its business. The website serves as a marketing tool, but depending on the quality and the design, it can be either positive or negative for a company’s business. This means that developing a responsive website doesn’t end the story, it needs to be checked and verified frequently. Testing plays a vital role in ensuring that the company is providing great digital customer experience to every customer!