Responsiveness testing: Challenges and tools for a perfect web design

It is now an unquestionable reality that life on the Internet does not take place in the dimensions of desktop computer screens. With the advent of mobile phones, tablets and the diversity of screens within smart TVs, website visitors are moving between different devices that have different resolutions.

That’s why responsive design, i.e. design that is able to adapt to the user’s preferred screen size, is becoming an important part of developing and testing websites and applications. In the following article, we’ll discuss the challenges of testing responsive design and introduce the tools that will guide you in achieving optimal responsive web design.

Basics for responsive web design

Flexible grid

Responsive design starts with a flexible grid system. Instead of using fixed column widths, relative units such as percentages or viewport width (vw) are used to create the grid. This allows the content to adapt proportionally to the screen size.

Media Queries

Media queries are sets of rules in Cascading Style Sheets (CSS) that allow you to apply styles according to certain conditions, such as screen width, device type, or resolution. Use them to adjust layouts, fonts, images and other features for different screens.

Flexbox and Grid Layout

CSS flexbox and grid layout are advanced techniques for arranging the content of a web page. Flexbox is ideal for aligning and arranging elements in a row or column, while grid layout allows you to create complex grids for content placement.

Relative units

Use relative units like REM to define font size and element placement. These units change with respect to the font size of the parent item, allowing for more flexible content layout.

Retina and vector images

Use vector and high-resolution (Retina) images to ensure that the quality of images on the page does not degrade on large screens.

Hide and view content

Use CSS to hide or show certain content based on screen size. This is useful for hiding or showing navigation menus, sidebars or other elements that would take up too much space on small screens.

Challenges of testing responsive design:

1. Different devices and screen sizes

For users accessing the web app across a variety of devices and screens, it is essential to ensure that the site displays correctly on all platforms, regardless of size.

2. Different browsers

Different browsers (e.g. Chrome, Firefox, Safari, Edge) have different standards and their own interpretation of the code. It is important to verify that the design works correctly on all major browsers.

3. Testing on real devices

Browser simulations can be useful, but they are not 100% reliable. Testing on real devices is essential for quality assurance.

4. Interacting with touchscreens

If the web app is available on touch devices, you need to verify that all interactions (clicks, scrolling) work smoothly.

5. Testing in multiple languages and text sizes

For international applications, it is important to ensure that both text and graphics look good and can be read in different languages and font sizes.

6. Screen orientation

The devices can be used in portrait (portrait) or landscape (landscape) mode. The design should be able to respond to these changes in orientation.

Responsiveness test – discover 6 useful tools


Responsinator is an online tool for testing responsive web design. It allows developers and designers to see how the site displays on different devices, including mobile phones, tablets and desktops.

Responsinator provides interactive testing, ease of use with no registration required, and a variety of display modes. This tool allows you to easily enter the URL of a page and view it on different devices. You can interact with the page to see how it behaves.

Benefits: fast, simple; tests multiple devices

Cons: Less accuracy; limited features.

Price: Free.

Responsinator is an online tool for testing responsive web design.

Google DevTools Device Mode

If you’re interested in testing responsive design on websites, you should definitely be familiar with a tool called Google DevTools Device Mode. Whenever you decide to use this tool, just open a web page in Google Chrome. Then simply press F12 or right click on the page and select “Check” to open the developer tools. Click on the device icon in the top right corner of the toolbar. This launches Device Mode and opens a new panel with lots of useful features.

First, you can choose from a variety of preset devices, such as different smartphone and tablet models. You can set your own screen size and resolution if you want.

And now the best part – you can see how your site looks on different devices. You can interact with the site, click on links and test its features on different screens. You can also emulate touch gestures, device orientation changes and even geolocation. You’ll find out how your site behaves in different usage scenarios.

Google DevTools Device Mode is an invaluable tool for developers who care about responsive design. It will help you identify and solve problems before your site reaches users.

Benefit: Integrated directly into Chrome; simulates different screen resolutions and devices.

Cons: Limited to Chrome functionality; can’t accurately simulate all device features.

Price: Free.

Google DevTools Device Mode is an invaluable tool for developers who care about responsive design.


This paid tool offers access to many different devices and browsers for testing. It’s a great option for businesses and design teams, as the cost of using this tool is quite high. BrowserStack’ s official site can be found here. In the last article, we reviewed BrowserStack.

BrowserStack offers you a wide range of devices, including smartphones, tablets and different browser versions. When you select a device, you’ll see your page on that device’s screen. You can interact with it and test its features to see if everything works properly.

One of the big advantages of Browser Stack is that it lets you test on real devices, not just emulation. This means you’ll get accurate results and see what your site looks like on real devices.

Plus, Browser Stack lets you test on multiple devices at the same time, saving you a lot of time. You can choose multiple devices and test your site on all of them at once.

So, if you’re interested in responsive design and want to make sure your website looks good on all devices, BrowserStack is the tool to help. Try it and see how easy and effective it is.

Benefits: high accuracy, wide range of supported devices and browsers.

Cons: Higher cost, can be complex for beginners.

Price: from 29 USD/month for an individual license (for a team subscription the price per individual is lower)

BrowserStack offers you a wide choice of devices, including smartphones, tablets and different browser versions


Ghostlab allows simultaneous testing on multiple devices and browsers. It is ideal for teamwork.

How to get started? First download and install Ghostlab on your PC. Then open Ghostlab and add the URL of the website you want to test.

Now you can choose which devices and browsers you want to test your site on. Ghostlab offers you a wide range of devices, including smartphones, tablets and different browser versions.

When you select your devices, Ghostlab will display your website on all of them at the same time. You can see how your site looks on different screens and check that everything is working properly.

In addition, Ghostlab allows you to synchronise control between all the devices you’re testing. So you can click on a link on one device and see how your site behaves on all your other devices.

Ghostlab also allows you to take screenshots of all devices tested, which can help you debug and fix bugs.

The link to download ghostlab can be found here.

Benefit: Synchronized testing across multiple devices, integrated debugging tools.

Cons: Requires installation, less intuitive interface.

Price: 7 day trial feature, then $49 for an individual license (lower price per individual for team subscriptions)

Responsive Design Checker

Responsive Design Checker is another in the range of free online tools. Its user interface is fast and intuitive, to use it, just enter the URL of a web page into the tool and choose from a predefined list of screen resolutions or customize your own. A useful feature is the ability to create screenshots for designs.

Benefits: free, easy to use, quick look at responsiveness.

Cons: Limited accuracy, does not allow testing on native applications.

Price: Free

Responsive Design Checker is a free, easy to use, quick look at responsiveness.


We hope this article has given you a good overview of what responsive testing means and what tools are available to perform it effectively. Don’t forget that responsive design isn’t just about aesthetics. It’s about providing a quality experience for all users, regardless of what device they use. And this is something that no web developer, designer or website owner can afford to ignore.

So, don’t hesitate to start testing your web projects. And remember, good design is responsive design.

About the author

Katarína Kučáková

Software Test Engineer

Moja cesta k testovaniu softvéru sa začala v roku 2019 až po štúdiu ekonómie a pracovných skúsenostiach v iných odvetviach. To mi pomohlo vnímať IT svet v rôznych súvislostiach. Ten totiž ponúka neustále nové výzvy, pre ktoré rada hľadám riešenia. Obľubujem oddych pri čítaní, turistiku alebo lyžovanie. LinkedIn

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