CSS Grid and Flexbox are both powerful layout tools, but they solve different problems. Understanding when to use each will make you a more effective developer. Let’s break down the differences.

The Key Difference

The fundamental difference is simple:

• Flexbox is one-dimensional: it handles layout in a single direction (row OR column)
• CSS Grid is two-dimensional: it handles layout in both directions (rows AND columns)

When to Use Flexbox

Flexbox excels at distributing space along a single axis. Use it for:

1. Navigation Bars

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

Perfect for spreading items across a header with even spacing.

2. Card Components

.card {
  display: flex;
  flex-direction: column;
}

.card-content {
  flex: 1; /* Takes up remaining space */
}

.card-footer {
  margin-top: auto; /* Pushed to bottom */
}

Great for ensuring buttons stay at the bottom regardless of content height.

3. Centering Content

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

The easiest way to center something both horizontally and vertically.

4. Form Layouts

.form-row {
  display: flex;
  gap: 1rem;
}

.form-row input {
  flex: 1;
}

Perfect for side-by-side form fields that grow to fill available space.

When to Use CSS Grid

CSS Grid is built for two-dimensional layouts. Use it for:

1. Page Layouts

.page {
  display: grid;
  grid-template-areas:
    "header header header"
    "sidebar main aside"
    "footer footer footer";
  grid-template-columns: 200px 1fr 200px;
  grid-template-rows: auto 1fr auto;
  min-height: 100vh;
}

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

Grid makes complex page layouts simple and maintainable.

2. Image Galleries

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

Automatically creates responsive columns that fill the container.

3. Dashboard Layouts

.dashboard {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
}

.widget-large {
  grid-column: span 8;
}

.widget-small {
  grid-column: span 4;
}

Perfect for complex layouts where items span multiple rows and columns.

4. Overlapping Elements

.hero {
  display: grid;
}

.hero > * {
  grid-area: 1 / 1; /* All children in same cell */
}

.hero-image {
  z-index: 1;
}

.hero-text {
  z-index: 2;
  align-self: center;
  justify-self: center;
}

Grid makes overlapping elements easier than absolute positioning.

Can You Use Both Together?

Absolutely! They complement each other perfectly:

/* Grid for overall page layout */
.page {
  display: grid;
  grid-template-columns: 250px 1fr;
}

/* Flexbox for navigation within sidebar */
.sidebar nav {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* Grid for main content area */
.main {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

/* Flexbox within each card */
.card {
  display: flex;
  flex-direction: column;
}

Flexbox Cheat Sheet

Common Flexbox properties:

.flex-container {
  display: flex;
  flex-direction: row; /* row, column, row-reverse, column-reverse */
  justify-content: flex-start; /* flex-start, center, space-between, space-around */
  align-items: stretch; /* stretch, flex-start, center, flex-end */
  flex-wrap: nowrap; /* nowrap, wrap, wrap-reverse */
  gap: 1rem;
}

.flex-item {
  flex: 1; /* flex-grow flex-shrink flex-basis */
  align-self: auto; /* Override container's align-items */
}

CSS Grid Cheat Sheet

Common Grid properties:

.grid-container {
  display: grid;
  grid-template-columns: 1fr 2fr 1fr; /* Or repeat(3, 1fr) */
  grid-template-rows: auto 1fr auto;
  gap: 1rem; /* Or row-gap and column-gap separately */
  grid-template-areas:
    "header header header"
    "sidebar main aside"
    "footer footer footer";
}

.grid-item {
  grid-column: 1 / 3; /* Start / End */
  grid-row: 2 / 4;
  /* Or use span: */
  grid-column: span 2;
  /* Or use areas: */
  grid-area: header;
}

Decision Matrix

Scenario	Tool	Why
Navigation bar	Flexbox	Single row of items
Card component	Flexbox	Single column layout
Page layout	Grid	Multiple rows and columns
Image gallery	Grid	Automatic responsive grid
Centering	Either	Both work, Flexbox is simpler
Form fields	Flexbox	Single row, dynamic widths
Dashboard	Grid	Complex positioning needed
List with actions	Flexbox	Space-between alignment

Browser Support

Both have excellent browser support:

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

For production use in 2025, you can safely use both without worrying about compatibility.

Practice Exercise

Try building a blog layout:

1. Use Grid for the overall page structure
2. Use Flexbox for the header navigation
3. Use Grid for the blog post grid
4. Use Flexbox inside each blog card

Resources

• CSS Tricks: A Complete Guide to Flexbox
• CSS Tricks: A Complete Guide to Grid
• Flexbox Froggy - Learn Flexbox through a game
• Grid Garden - Learn Grid through a game

Conclusion

There’s no “better” tool - they’re designed for different purposes:

• Flexbox: One-dimensional layouts, content-driven sizing
• Grid: Two-dimensional layouts, container-driven sizing

Master both, use them together, and you’ll be able to tackle any layout challenge with confidence!