CSS Flexbox Generator Online — Build Flex Layouts Visually Free

What Is CSS Flexbox?

Flexbox (Flexible Box Layout) is a CSS layout model designed for arranging items in a single dimension — either as a row or a column. It's the standard for creating navigation bars, card rows, centered layouts, and responsive UI components. Flexbox properties are split between the container and the children:

• Container properties: display:flex, flex-direction, justify-content, align-items, flex-wrap, gap.
• Child properties: flex-grow, flex-shrink, flex-basis, align-self, order.

How to Use the CSS Flexbox Generator Online

1. Open the flexbox generator at DevKits.
2. Set the number of child items in the preview container.
3. Adjust container properties: flex-direction, justify-content, align-items, flex-wrap, and gap.
4. Select individual children to set per-item properties: flex-grow, flex-shrink, flex-basis.
5. See the layout update in real time as you change values.
6. Copy the generated CSS for both container and children.

Key Flexbox Properties Explained

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

.child {
  flex: 1;                    /* shorthand for flex-grow: 1, flex-shrink: 1, flex-basis: 0 */
  align-self: flex-end;       /* override parent align-items for this child */
}

Key Features

• Visual layout preview: real containers and children that reflow as you adjust settings.
• All container properties: direction, wrap, justify, align, gap.
• Per-child property controls: grow, shrink, basis, order, align-self.
• Responsive preview: test how the layout behaves at different container widths.
• Common layout presets: navbar, card row, centered page, sidebar layout.
• Full CSS output: complete, copy-ready CSS for container and all children.

Common Flexbox Patterns

Horizontally and Vertically Centered

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

Navigation Bar with Logo Left, Links Right

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

Responsive Card Row

.cards {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}
.card { flex: 1 1 300px; }

Frequently Asked Questions

When should I use Flexbox vs CSS Grid?

Flexbox is one-dimensional (rows OR columns). Use it for: navigation bars, button groups, card rows, centering content. Grid is two-dimensional (rows AND columns simultaneously). Use it for: page layouts, dashboards, image galleries. When in doubt: use Flexbox for components, Grid for page structure.

What does flex: 1 mean?

flex: 1 is shorthand for flex-grow: 1; flex-shrink: 1; flex-basis: 0. It means the item grows to fill available space, shrinks if needed, and starts with 0 base size. All items with flex: 1 share available space equally.

How do I make a flex item take up remaining space?

Use flex-grow: 1 or flex: 1 on the item you want to expand. If only one item has flex-grow > 0, it takes all remaining space. If multiple items have flex-grow, space is divided proportionally.

What is the gap property in flexbox?

gap sets the spacing between flex items (and grid cells). It's equivalent to applying margin between items but without affecting outer edges. Use gap: 1rem for equal gaps, or gap: 1rem 2rem for different row and column gaps.

Is the tool free?

Yes, completely free with no signup required.