Mobile First Design

Mobile First Design is a web development approach where a website is designed and developed for mobile devices first, then progressively enhanced for tablets, laptops, and desktop screens.

Instead of starting with a large desktop layout and shrinking it down, developers begin with the smallest screen and add features as screen size increases. The supporting concepts are explained in CSS Media Queries and Responsive Layout.

This approach is recommended because:

• Mobile users make up a large percentage of web traffic
• Mobile layouts are simpler and easier to optimize
• It improves performance and accessibility
• It aligns with modern responsive design practices

Syntax

In Mobile First Design, the base CSS targets mobile devices, and media queries are used to enhance the layout for larger screens.

.element {
    width: 100%;
}
@media (min-width: 768px) {
    .element {
        width: 50%;
    }
}