CSS Flexbox Generator

Build responsive, flexible layouts with the CSS Flexible Box Module. Adjust container properties (direction, wrap, alignment) and item properties (order, grow, shrink, basis). See changes instantly and copy production‑ready CSS.

Zero server processing – All layout adjustments happen locally in your browser. No data is tracked or stored.
Interactive Flex Canvas
Reset
? Row / Space-between
? Column Center
? Wrap + Grow
? Card Gallery
? Navbar Layout
Item 1
Item 2
Item 3
Item 4
Drag bottom-right corner to test responsiveness
Flex Container Properties
gap: 0px
Flex Item Settings
Generated CSS
/* Flexbox CSS will appear here */

Understanding Flexbox: The Modern Layout Model

The CSS Flexible Box Layout (Flexbox) was designed to provide a more efficient way to lay out, align, and distribute space among items in a container, even when their sizes are unknown or dynamic. Unlike block-based layouts, flexbox gives you complete control over direction, alignment, order, and flexibility. It has become the cornerstone of responsive web design and component-based UI architectures.

Browser Compatibility

PropertyChromeFirefoxSafariEdgeNotes
display: flex29+28+9+12+Full support
flex-wrap29+28+9+12+Full support
gap (flex)84+63+14.1+84+Modern browsers only
align-content29+28+9+12+Full support

Real-World Code Examples

? Responsive Navigation Bar
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  padding: 1rem;
  gap: 1rem;
}
.nav-links {
  display: flex;
  gap: 1.5rem;
}
@media (max-width: 768px) {
  .navbar { flex-direction: column; text-align: center; }
  .nav-links { flex-direction: column; gap: 0.5rem; }
}
? Responsive Card Gallery
.card-gallery {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  justify-content: center;
}
.card {
  flex: 1 1 280px;  /* grow, shrink, basis */
  max-width: 350px;
  padding: 1rem;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
? Sticky Footer Layout
body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
main {
  flex: 1;  /* pushes footer to bottom */
}
footer {
  background: #333;
  color: white;
}

Common Pitfalls & Debugging Tips

  • ❌ Items overflowing container? Check if flex-wrap: wrap is set. Without wrap, items will try to fit on one line.
  • ❌ flex-grow not working? Ensure container has extra space (fixed width/height) and flex-basis isn't preventing distribution.
  • ❌ gap not showing? Gap in flex containers requires browser version Chrome 84+, Firefox 63+, Safari 14.1+. Use margins as fallback.
  • ❌ align-content has no effect? align-content only works when flex-wrap is set to wrap and there are multiple lines.
  • ❌ order breaks accessibility? Visual order changes via order property do NOT affect DOM order — screen readers follow DOM order. Use cautiously.

Core Flexbox Properties Reference

PropertyDescriptionKey Values
flex-directionDefines main axis direction.row, column, row-reverse, column-reverse
flex-wrapControls whether items wrap onto multiple lines.nowrap, wrap, wrap-reverse
justify-contentAlignment along main axis.flex-start, center, space-between, space-around, space-evenly
align-itemsAlignment along cross axis (single line).stretch, flex-start, center, baseline
flex-growAbility for an item to grow relative to siblings.Number (0 or positive)
flex-shrinkAbility to shrink when space is limited.Number (default 1)
flex-basisInitial main size of a flex item.auto, %, px, rem
orderControls visual ordering independent of source.Integer (default 0)

Frequently Asked Questions

justify-content aligns items along the main axis (defined by flex-direction), while align-items aligns them along the cross axis. For row direction, main axis is horizontal, cross axis vertical.

Ensure the container has enough extra space and no conflicting flex-basis: auto may limit distribution. Use flex-basis: 0% to force equal distribution.

Absolutely. The generated CSS is clean, follows standards, and can be copied directly into your stylesheets. Always test in target browsers.

flex-basis: auto uses the item's content size as the starting point. flex-basis: 0% ignores content size, allowing items to distribute space purely based on flex-grow ratios.
References & Further Reading: MDN Flexbox · W3C Specification (Level 1) · CSS-Tricks Complete Guide
Tool version 2.0 | Last updated: March 2026 | Compatible with modern browsers (Chrome 84+, Firefox 63+, Safari 14.1+, Edge 84+)