Responsive design: why all devices matter equally

Why all devices matter

"Mobile-first" suggests mobile is most important. But that is not how people use websites. Desktop users, tablet users, and mobile users all have different needs, different contexts, and different reasons for visiting. Your site should work well for all of them, not prioritise one over another.

Responsive design means sites that adapt to different screen sizes. It does not mean mobile is more important than desktop, or desktop is more important than mobile. It means all devices matter equally.

Different devices, different contexts

People use different devices for different reasons:

• Desktop: Research, comparison shopping, detailed reading, complex tasks.
• Tablet: Browsing, casual reading, media consumption, comfortable viewing.
• Mobile: Quick checks, on-the-go access, simple actions, location-based searches.

Each context matters. Desktop users need detailed information and clear navigation. Mobile users need quick access and simple interactions. Tablet users need comfortable viewing and smooth scrolling. All of these are equally important.

Why mobile-first is limiting

Mobile-first puts mobile in people's heads as the most important device. But this creates problems:

• It creates hierarchy: If mobile is "first", desktop and tablet feel secondary.
• It limits design: Starting with mobile constraints can limit what works well on larger screens.
• It misses context: Desktop users have different needs than mobile users. Both matter equally.
• It assumes mobile is primary: But many users prefer desktop, especially for research and complex tasks.

Instead of "mobile-first", think "all devices equally". Design and build for desktop, tablet, and mobile together, not one before the others.

How responsive design should work

Responsive design means sites that adapt to different screen sizes. It should work like this:

• Design for all screen sizes: Layouts, typography, and interactions work well on desktop, tablet, and mobile from the start.
• Build responsively: Code that adapts smoothly to any screen size, without feeling like a mobile site stretched to desktop or a desktop site squeezed to mobile.
• Test on real devices: Not just browser resizing, but actual phones, tablets, and desktops.
• Performance for all: Fast-loading pages, optimised images, and efficient code that works well on every device [1]Source 1 .

What responsive design affects

Layout

• Flexible grids: Layouts that adapt to screen width, not fixed to one size.
• Content reflow: Content that rearranges naturally on different screen sizes.
• Navigation: Navigation that works well on desktop (full menu) and mobile (hamburger or simplified menu).

Typography

• Readable text: Text that is readable on all devices (at least 16px, good contrast).
• Responsive sizing: Font sizes that scale appropriately for different screen sizes.
• Line length: Lines that are not too long on desktop, not too short on mobile.

Images and media

• Responsive images: Different image sizes for different screen sizes.
• Optimised: Images optimised for all devices (modern formats, appropriate sizes).
• Lazy loading: Images that load as people scroll, not all at once.

Performance

• Fast on all devices: Pages that load quickly on desktop, tablet, and mobile [2]Source 2 .
• Efficient code: Lean HTML, CSS, and JavaScript that works well on every device.
• Optimised assets: Images, fonts, and scripts optimised for all screen sizes.

Best practices for cross-device design

Design

• Design for all devices: Consider desktop, tablet, and mobile from the start.
• Touch-friendly: Buttons and links are at least 44px tall for easy tapping on mobile and tablet.
• Readable text: Text is readable without zooming (at least 16px, good contrast).
• No horizontal scrolling: Content fits the screen width on all devices.
• Consistent experience: Same content, same functionality, same quality on every device.

Performance

• Optimise images: Compress, resize, use modern formats for all devices.
• Minimise scripts: Only include scripts you actually need.
• Fast hosting: Use fast hosting or CDN.
• Test performance: Pages load fast on desktop, tablet, and mobile.

Testing

• Test on real devices: Not just browser resizing, but actual phones, tablets, and desktops.
• Test on different browsers: Chrome, Safari, Firefox, Edge.
• Test touch interactions: Buttons, links, forms work with touch on mobile and tablet.
• Test keyboard navigation: Sites work with keyboard on desktop.

Common mistakes

• Mobile-first thinking: Designing for mobile first and treating desktop as an afterthought.
• Desktop-first thinking: Designing for desktop and trying to make it work on mobile.
• Hiding content on mobile: Hiding important content because "there is not enough space".
• Small touch targets: Buttons and links that are too small to tap easily on mobile and tablet.
• Slow images: Large, unoptimised images that slow pages on all devices.
• Complex navigation: Navigation that is hard to use on mobile or desktop.
• Inconsistent experience: Different content or functionality on different devices.

Summary

Responsive design means sites that adapt to different screen sizes. It should treat desktop, tablet, and mobile with equal importance, not prioritise one over another.

All devices matter because people use different devices for different reasons. Desktop users need detailed information, mobile users need quick access, tablet users need comfortable viewing. All of these are equally important.

Instead of "mobile-first" or "desktop-first", think "all devices equally". Design and build for desktop, tablet, and mobile together, with the same attention, the same quality, and the same performance.

For more on responsive design, see cross-device design expertise. For more on performance, see fast websites: what fast means and Core Web Vitals for business owners. For help building responsive sites, see website build services or get in touch to discuss your project.