Mobile-First Design with Tailwind CSS

1. Why Mobile First?

• Most users visit websites on mobile devices first.
• Easier to scale up a layout than scale it down.
• Better performance and less unused code on mobile.

2. Default Styles Apply to Mobile

Any utility class without a prefix is applied to **all screen sizes**, starting from the smallest. For example:

<div class="text-sm md:text-base lg:text-xl">Responsive Text</div>
            

In this case:

• text-sm is the default (mobile)
• md:text-base applies on screens ≥ 768px
• lg:text-xl applies on screens ≥ 1024px

3. Tailwind’s Breakpoints

Tailwind provides mobile-first breakpoints:

• sm – 640px
• md – 768px
• lg – 1024px
• xl – 1280px
• 2xl – 1536px

These breakpoints allow you to scale layouts and styles progressively:

<div class="p-2 md:p-4 lg:p-6">Adaptive Padding</div>
            

4. Real-World Example

A responsive card layout might look like:

<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
    <!-- Cards here -->
</div>
            

This layout will show 1 card per row on mobile, 2 on medium screens, and 3 on large screens.

5. Summary

• Default utility classes are mobile styles.
• Use responsive prefixes to scale designs up.
• This approach leads to simpler and more maintainable code.

Conclusion

Embracing mobile-first design ensures your Tailwind-powered sites are performant, user-friendly, and scalable — from the smallest phone to the largest desktop.