CSS Grid vs Flexbox: When to Use Each

Two of the most powerful CSS layout methods are CSS Grid and Flexbox. While they can sometimes achieve similar results, each has its strengths and ideal use cases. Let's explore when to use each.

Understanding the Fundamentals

Flexbox: One-Dimensional Layout

Flexbox is designed for one-dimensional layouts - either a row or a column. It excels at distributing space and aligning items along a single axis.

.flex-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

CSS Grid: Two-Dimensional Layout

CSS Grid is designed for two-dimensional layouts, handling both rows and columns simultaneously. It's perfect for complex layouts where you need precise control over placement.

.grid-container {
  display: grid;
  grid-template-columns: 1fr 2fr 1fr;
  grid-template-rows: auto 1fr auto;
  gap: 1rem;
}

When to Use Flexbox

1. Navigation Bars

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem;
}

.nav-links {
  display: flex;
  gap: 1rem;
  list-style: none;
}

2. Card Components

.card {
  display: flex;
  flex-direction: column;
  padding: 1rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.card-content {
  flex: 1;
}

3. Centering Content

.center {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

When to Use CSS Grid

1. Page Layouts

.page-layout {
  display: grid;
  grid-template-areas:
    "header header header"
    "sidebar main main"
    "footer footer footer";
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
}

.header { grid-area: header; }
.sidebar { grid-area: sidebar; }
.main { grid-area: main; }
.footer { grid-area: footer; }

2. Image Galleries

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

3. Form Layouts

.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.full-width {
  grid-column: 1 / -1;
}

Combining Both

Often, the best approach is to use both together:

/* Grid for overall layout */
.app {
  display: grid;
  grid-template-areas:
    "header"
    "main"
    "footer";
}

/* Flexbox for header content */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Grid for main content */
.main {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 2rem;
}

/* Flexbox for sidebar items */
.sidebar ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

Decision Framework

Use Flexbox when:

• You need to align items in one dimension
• You want to distribute space evenly
• You're building navigation components
• You need to center content
• You're working with dynamic content sizes

Use CSS Grid when:

• You need two-dimensional control
• You're creating page layouts
• You need precise item placement
• You're building complex components
• You want to create responsive layouts without media queries

Modern Browser Support

Both CSS Grid and Flexbox have excellent browser support:

• Flexbox: Supported in all modern browsers
• CSS Grid: Supported in all modern browsers (IE11+ with prefixes)

Conclusion

CSS Grid and Flexbox are not competing technologies - they're complementary tools that solve different layout challenges. Understanding their strengths helps you choose the right tool for each situation, often using them together in the same project.

The key is to start with the content and layout requirements, then choose the most appropriate method. With practice, you'll develop an intuition for when to reach for Grid versus Flexbox.