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Home Guide Responsive Web Design: What is it and How to Use it?

Responsive Web Design: What is it and How to Use it?

By Shreya Bose, Community Contributor -

You might already know this, but this important fact cannot be overstated: More than half of all internet users worldwide access the web via mobile devices. 

Data report for Apr 2023 on cellular network usageSource

  • “Mobile devices” doesn’t just refer to cell phones, but also laptops, hand-held tablets, and even smartwatches. Each device has a different screen size and, more importantly, different image resolutions. 
  • In other words, if your website is not equipped with responsive web design, it will look great on some of these devices, and completely break on others.

In this article, we’ll take you through a 101-style introduction to responsive web design, discuss why it’s a non-negotiable necessity in modern web design, and help you implement it. 

Let’s dive in. 

What is Responsive Web Design?

Responsive web design refers to a web design approach that enables your website content to “respond” to and adapt to the screen and window sizes of its accessed devices. Responsive design websites will morph, as required, so they can appear flawlessly on the end-user’s devolve, regardless of screen size and orientation.

For example, columns of content in a horizontal layout look pretty great on desktop and laptop screens, but horizontal columns on a mobile phone or a smaller tablet will be too wide. The user won’t be able to see all the content; even if they do, the content might be distorted and unreadable. 

  • Responsive web design ensures that the content columns appear only on larger screens, while also rearranging itself to appear in a different, mobile-friendly layout on smaller device screens. 
  • Within the ambit of web development and mobile web, responsive design involves heavy usage of flexible grids, layouts, images, and targeted use of CSS media queries. 
  • The design switch should be seamless and automatic between devices. 
  • When implementing this design, devs must also be cognizant of issues like the possibility of a VPN for iOS on a user’s iPad. In such cases, the website shouldn’t automatically block the user’s access, unless there are legal ramifications for the site owners in doing so.

Benefits of Responsive Web Design

Here are some of the core benefits of a Responsive Web Design:

  1. It provides a consistent user experience across different devices and screen sizes. With a responsive design, users can enjoy the content seamlessly as they switch from one device to another without missing out on the user experience.
  2. It improves engagement even on smaller screen sizes.
  3. It reduces bounce rate of the website.
  4. It reduces churn rate of the customers.
  5. Allows customers to access content on the go.

Why do websites need Responsive Web Design?

If you’re alive in 2023, you know that people use thousands of different devices to access the net worldwide. Your website will have to look great on many physical endpoints, be it iPhones or Android, tablets or smartwatches. 

Mobile advertising expenditure worldwide 2018 to 2023Source

  • Additionally, mobile-friendliness is one of the key parameters by which your websites are rank on SERP by Google. 
  • If your site doesn’t adapt itself to most mobile devices, you’ll be at a disadvantage against your competitors, who are sure to align their sites for mobile visitors. 
  • And…yes, there’s more. Mobile ad spending and organic SEO efforts have magnified enormously as advertisers and content marketers scramble to get the attention of mobile viewers. 
  • Unless you align with these tactics, you’ll lose out on serious, bank-breaking revenue. 

By not employing responsive designs, you’ll be unable to maximize your conversions and ROI. You won’t reach most of your potential audience and lose money on ad spend.

Core Principles of Responsive Web Design

Some of the core principles of a responsive web design are:

  1. Fluid Grid Layouts: Use fluid CSS Grids instead of fixed width grids. For a fluid grid use relative units like percentages instead of fixed units like pixels to define column widths and spacing.
  2. Responsive Images: Use Responsive images so that they can adjust based on the screen dimensions. This would help use access the images completely without compromising on the user experience.
  3. CSS Media Queries: Media queries enable you to create a layout that is based on the device specifics such as screen width, orientation, and resolution.
  4. Breakpoints: Breakpoints are specific screen widths at which the layout of a website changes to accommodate different screen sizes. These breakpoints are defined using media queries and are used to reorganize content and adjust styling to ensure readability and usability.
  5. Mobile-first approach: designing for mobile devices first and then gradually enhancing the design for larger screens. It ensures that the core content and functionality are accessible on smaller screens, and additional features are added as screen size increases.

Fundamentals of Responsive Web Design (for the Web Developer)

Responsive web design requires the following components to resize a website for different device screens successfully. 

1. CSS and HTML

CSS & HTML are two programming languages that form the essential backbone of responsive web design. They’re used to set the control and layout of a web page in different browsers. 

HTML sets each web page’s structure, design elements, and content. A simple example of HTML code would be the snipper below, used to add images to websites:

<img src="image.gif" alt="image" class=”full-width-img”>

While it’s possible to set and control primary attributes like height and width, it’s easier to do so with CSS. You can edit the design and layout of each element and even include CSS code in a <style> section of HTML documents or as an independent stylesheet file. 

As an example, here’s the code to edit the width of all HTML images at the element level:

img {
width: 100%;

Conversely, add a period and target the specific class “full-width-img” from the previous example:

full-width-img {
width: 100%;

Similarly, you can set design aspects at more granular levels, beyond just height, width and color. Combining CSS with media queries sets the foundation for a responsive website. 

2. Media Queries

A pivotal part of CSS3, a media query is a technique that allows content to adapt to various screen sizes and resolutions. Fundamentally, it checks if a user’s viewport is wide enough (or too wide or not enough) before running the right code to render the right site version for that screen. 

For example, observe the snippet below:

@media screen and (min-width: 780px) {
.full-width-img {
margin: auto;
width: 90%;

In case of screens 780px and wide, this code mandates that “full-width-img” class images occupy a large proportion of the screens and are adjusted to the center with wide margins. 

3. Fluid Layouts

In the earlier days of web design, it was possible to specify static values, like 600px or 900px for each HTML element. But as part of modern web design, dynamic websites require equally dynamic values (eg, a % of viewport width) to render in their entirety. 

Fluid LayoutsSource

This technique dynamically adjusts container element sizes to screen size, and displays the accurately sized elements that fit each user screen. 

4. Flexbox Layout

Despite its flexibility, fluid layouts weren’t malleable enough for certain folks in the domain. They adopted Flexbox, a CSS module enabling more efficiency in laying out different elements. The big perk is that flexbox layouts work without knowing the size of elements within each container.

These flex containers will resize items within them to fit screens. Moreover, they come with properties you cannot edit with general HTML elements.  

Responsive layout diagram Source

5. Responsive Images

You can make images responsive with the same fluid layout outlined above. But, in this technique, users’ devices still download each full-sized image, on both desktop and mobile. In order to ensure that different devices received the images scaled to their size/resolution, use the HTML srcset attribute within img tags. 

That way, you can direct the code to choose from more than one image size.

<img srcset="large-img.jpg 1024w,
middle-img.jpg 640w,
small-img.jpg 320w"

Steps in Creating Responsive Web Design for a Website

1. Define a Viewport

You have to define a meat viewport tag to instruct the browser on how to reshape and resize the content depending on the screen size it is rendering for. All meta tag information will be slotted into the content attribute. 

Set the initial-scale, minimum, and maximum-scale to establish the limits of content scaling. Your web page cannot be resized infinitely.

After defining the viewport, modify page elements to fit the defined sizes. When doing so, bear in mind that users scroll vertically. So, stack your elements accordingly, especially when optimizing for mobile screens. 

2. CSS Media Queries

Don’t set fixed widths for any of them when resizing page elements to fit your new viewport. Since content must also render in a specific order, different properties must be associated with the same DOM element. This is where CSS media queries come in. 

As mentioned, media queries allow web pages to adjust to different viewports. Let’s say you’ve set the following parameters:

  • When device width is less than 640px, font size is 15pt.
  • When device width is less than 480px, font size is 12pt.

Your CSS code can be configured to implement these standards using the media attribute:

  • The engine loads a stylesheet to match the width of the device screen. This is done in the <link> tag using the media attribute.
  • By the standards above,  the browser will utilize the stylesheet.css file only if the screen and device widths 640px or lower.
  • Use the @media keyword in CS3 to specify distinct CSS properties, which will operate based on screen filters. If you do this, you won’t have to create separate style sheets and files for different screen sizes. 
  • It is also possible to run media queries adjusted to the orientation of the user devices. However, the orientation attribute is still unsupported by many devices. It’s much easier for devs to combine max-device-width and min-device-width instead of defining element sizes on different screens.

3. Optimize Text

You can establish text size using px or pt, or keep size relative using em, rem, or %. Place text properties within media queries to fit variant viewport dimensions.

Before setting text dimensions, ask two foundational questions:

  • How many words should be in a single line when your site is rendering on the smallest device screen?
  • What is the smallest legible text size for a specific scale and viewport?

4. Responsive Images

Make images responsive by relating image width to the width of the container DOM element – so that the images resize according to the dimensions of the container element (which also resizes itself according to the viewport size).

Quick Note: This tactic involves a lot of performance overhead, especially on mobile screens. Optimizing images for mobile device context might be worthwhile, as it drives down latency and improves page load speed.

You could also create a back-end script displaying the appropriate image file to render within the current device and network capabilities.

5. Data Tables

If a table on your website has too many columns, it will force users to scroll horizontally on smaller viewports.

To prevent this, convert each row into a responsive element. Now, each row displays itself via multiple lines on smaller screens. You could also hide some columns, allowing users to click a button that displays the hidden columns. 

6. Navigation Menus

You can make navigation menus responsive by:

  • Converting links to a drop-down menu
  • Creating a menu normally hidden but becomes visible when the user swipes/clicks.

    Once you’ve acquainted yourself with the basics of responsive designs, head over to How to Create a Responsive Website to dig deeper into the process from end to end.

Best Practices for implementing Responsive Web Design

  • Define your target audience and their device preferences.
  • Create wireframes to visualize the layout and interactions.
  • Consider the content hierarchy and prioritize key elements for different screen sizes.
  • Start the design process by focusing on smaller screens and limited functionality.
  • Optimize content and features for a mobile-first design.
  • Optimize images, code, and resources to improve loading speed on different devices.
  • Use responsive design techniques like fluid grids and flexible media to adapt to larger screens.
  • Use HTML, CSS, and JavaScript to implement the responsive design.
  • Use real devices to test the design across various devices and screen sizes.
  • Ensure cross-platform visual consistency
  • Gather user feedback and analyze user behavior to identify areas for improvement.
  • Make iterative changes to enhance usability, performance, and accessibility.

Testing Responsive Design on Real Devices

Let’s say you’ve put together your first (or five hundredths) responsive website. You certainly won’t be releasing it for public browsing without testing it. But given that there are literally thousands of viewport sizes, screen orientations, and pixel counts your website has to “respond to”, do you need to buy/collect every single device before you can verify your site responsiveness?

Absolutely not. 

  • If a website has to be validated as responsive, it must be tested on multiple real browsers and devices. That is the only way to check the success of responsive design in real user conditions.

Responsive design checker

Instead of purchasing multiple devices, enter the URL into the checker and monitor what it looks like on different real devices, all online. The checker linked above offers responsive checking on devices such as iPhone X, Galaxy Note 10, iPhone 8 Plus, and more.

Browserstack Dashboard

If you want access to a truly exhaustible list of devices, sign up for free on BrowserStack’s Real Device Cloud

  • Get instant, on-demand access to 3000+ real browsers and devices. 
  • Check how your site’s responsive design renders on the latest devices and browsers, so you leave nothing to chance when releasing your website to your audience. 
  • No visual bugs, no distortions, and no frustrated users complaining (rightfully) next to their one-start review on Play Store or App Store. 

Free Responsive Test on Commonly Used Resolutions

Try testing the responsiveness of your website on real devices.

Responsive Website Testing

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