Modern CSS offers two powerful layout systems: Flexbox and Grid. Both are essential tools, but knowing when to use each can significantly improve your code quality.

Flexbox is ideal for one-dimensional layouts - either a row or a column. Use it for navigation bars, card lists, centering content, and form layouts where elements need to grow or shrink dynamically.

CSS Grid excels at two-dimensional layouts where you need control over both rows and columns. Think dashboard layouts, magazine-style pages, and complex responsive designs.

Key Differences:

  • Flexbox works on a single axis at a time; Grid works on both axes simultaneously
  • Flexbox is content-first (items determine layout); Grid is layout-first (grid defines placement)
  • Grid provides explicit gap control with grid-gap

When to Use Flexbox: Navigation menus, toolbars, card layouts, centering, form rows When to Use Grid: Page layouts, image galleries, dashboards, complex responsive designs

Pro tip: You can nest Flexbox inside Grid (and vice versa) for truly flexible layouts.