CSS Flexbox Generator

Generate CSS flexbox layouts free online with live visual preview. Adjust direction, justify-content, align-items, gap, and wrap, with ready-to-copy CSS code.

flex-direction

flex-wrap

justify-content

align-items

gap: 10px

Browser only.

How to Use This Tool

Set direction and wrapChoose how items flow and whether they wrap

Adjust alignment and gapControl spacing along both axes

Copy the generated CSSApply directly to your flex container

Seeing the Interaction Between Properties Live

Flexbox properties don't work in isolation -- justify-content behaves along whichever axis flex-direction defines as "main," which means understanding flexbox deeply requires seeing how these properties interact, not just reading each one's definition separately. This generator shows that interaction directly and immediately.

Main Axis Versus Cross Axis -- The Core Concept

Every flexbox layout has a main axis (set by flex-direction) and a perpendicular cross axis. justify-content always works along the main axis; align-items always works along the cross axis. Switching flex-direction from row to column doesn't change what these properties do -- it changes which physical direction (horizontal or vertical) each axis actually represents.

Flexbox and Grid as Complementary Tools

Flexbox handles one-dimensional layout arrangement elegantly -- a navigation bar, a row of cards, a column of stacked elements. For genuinely two-dimensional layouts needing precise row and column control together, CSS Grid is the more natural fit. Most real interfaces use both, applying each where it fits best.

Frequently Asked Questions

Flexbox properties interact with each other in ways that are genuinely easier to understand by seeing the result than by reading property definitions in isolation -- justify-content behaves differently depending on flex-direction, for instance, which a live preview makes immediately clear.

justify-content controls alignment along the main axis (horizontal in a row layout), while align-items controls alignment along the cross axis (vertical in a row layout) -- the two properties work perpendicular to each other, which is a common point of confusion when first learning flexbox.

Setting flex-direction to row makes horizontal the main axis and vertical the cross axis. Setting it to column swaps this entirely -- vertical becomes main, horizontal becomes cross -- which is exactly why justify-content and align-items can feel like they swap roles when you change direction.

Whether flex items are forced onto a single line (potentially shrinking to fit) or allowed to wrap onto multiple lines when they don't all fit at their natural size -- a meaningful behavioral difference for responsive layouts with many items.

Yes, they solve different problems well -- flexbox excels at one-dimensional layouts (a single row or column of items), while Grid excels at two-dimensional layouts (rows and columns together). Many real interfaces use both, choosing whichever fits each specific layout need.