How to Create a Full Screen Section Using CSS (Responsive 100vh Guide)

Full screen sections are everywhere in modern web design.

You’ll see them in:

• Landing Pages
• Hero Sections
• Portfolio Websites
• SaaS Homepages
• App Introductions

If you’ve ever wondered how developers make a section take up the entire screen height, the good news is that modern CSS makes it very simple.

In this tutorial, you’ll learn how to create a full screen section using CSS, including practical examples, common mistakes, and responsive techniques used in real projects.

What is a Full Screen Section?

A full screen section takes up the entire visible height of the browser window.

In CSS, this is usually done using:

The vh unit stands for:

viewport height

So:

means:

100% of the browser screen height

Basic Full Screen Section Example

HTML

CSS

Why Developers Use Flexbox Here

You’ll notice this example uses Flexbox.

That’s because Flexbox makes it much easier to:

• Center content
• Align elements vertically
• Create responsive layouts

Without Flexbox, vertically centering content used to require awkward CSS hacks.

Result

This creates a full screen hero section where the content stays perfectly centered both horizontally and vertically.

This layout is extremely common in modern websites.

How 100vh Works

A lot of beginners get confused by viewport units.

Here’s the simple idea:

Unit	Meaning
vh	viewport height
vw	viewport width

Example:

This means:

50% of the screen height

Full Screen Background Image Section

This is one of the most common real-world use cases.

CSS

Why background-size: cover Matters

Without this:

your image may:

• Stretch
• Repeat
• Look distorted

Most developers use cover for hero sections because it keeps the image visually balanced.

Responsive Full Screen Sections

In real projects, mobile responsiveness matters a lot.

Here’s a simple responsive setup:

Using:

Fixed heights can break layouts on smaller devices.

Viewport units are much more responsive.

2. Forgetting Mobile Issues with 100vh

Some mobile browsers handle 100vh differently because of the address bar.

Modern CSS now supports:

dvh stands for:

dynamic viewport height

This works better on modern mobile browsers.

Better Mobile-Friendly Version

Many modern developers now prefer dvh over vh.

Real Project Use Cases

Full screen sections are commonly used for:

• Hero banners
• Landing page intros
• Product showcases
• App download sections
• Portfolio websites

If you inspect modern SaaS websites, you’ll see this layout pattern almost everywhere.

Full Screen Section with Overlay

Here’s a more realistic design pattern.

HTML

CSS

This creates the dark overlay effect commonly used in hero sections.

Full Screen Section vs Full Width Section

Many beginners confuse these two.

Layout	Meaning
Full screen	Takes full screen height
Full width	Takes full screen width

Most hero sections use both.

Browser Support

Viewport units like:

• vh
• vw
• dvh

are supported in all modern browsers.

Which Method Should You Use?

For most modern projects:

✅ Recommended:

Fallback option:

Final Thoughts

Creating a full screen section using CSS is much easier today than it used to be.

For most layouts:

• Use Flexbox for alignment
• Use 100vh or 100dvh for height
• Avoid fixed heights

Once you understand viewport units, building modern landing pages and hero sections becomes much more straightforward.

Frequently Asked Questions (FAQs)

Q1. How do I make a section full screen in CSS?

Use:

or:

Q2. What does 100vh mean in CSS?

It means:

100% of the browser viewport height

Q1. Should I use vh or dvh?

For modern mobile-friendly layouts, dvh is usually better.