Flexbox Playground

Visually configure a CSS flexbox container and copy the generated CSS

Flex settings

Presets:

Live preview

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CSS

.flex-container {
  display: flex;
  flex-direction: row;
  justify-content: flex-start;
  align-items: stretch;
  flex-wrap: nowrap;
  gap: 8px;
}

Examples

Centered hero section

.flex-container {
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
  flex-wrap: nowrap;
  gap: 16px;
}

Centers items both horizontally and vertically — the classic pattern for a hero or modal.

Responsive wrapping card gallery

.flex-container {
  display: flex;
  flex-direction: row;
  justify-content: flex-start;
  align-items: stretch;
  flex-wrap: wrap;
  gap: 24px;
}

Cards wrap to new rows automatically and all stretch to the same height, ideal for a responsive grid of equal-height cards.

Details

CSS Flexbox is a one-dimensional layout model that makes it easy to align and distribute space among items in a container. This playground lets you tweak all the major flex-container properties — direction, justification, alignment, wrapping, and gap — and see numbered items react in real time. Everything runs locally in your browser; no data is ever sent anywhere.

Examples

Center a child in a column

Input
flex-direction: column
justify-content: center
align-items: center
Output
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;

Column direction stacks children vertically; centering on both axes puts the child in the middle of the container.

Space items evenly across a row

Input
flex-direction: row
justify-content: space-between
gap: 16px
Output
display: flex;
flex-direction: row;
justify-content: space-between;
gap: 16px;

space-between pushes the first and last items to the edges and distributes the rest, with a fixed gap between each.

About this tool

The Flexbox Playground is a visual configuration tool for CSS Flexbox containers. Adjust flex-direction, justify-content, align-items, flex-wrap, and gap through simple dropdowns and a slider, then watch numbered items react in the live preview — all without writing a single line of CSS by hand.

The generated output is a complete, production-ready .flex-container { display: flex; … } rule that you can paste straight into any stylesheet. Because all processing happens locally in your browser, no data ever leaves your device.

Whether you are learning how justify-content differs from align-items, prototyping a navigation bar, or debugging a wrapping layout, the Flexbox Playground gives you immediate visual feedback so you can apply Flexbox with confidence.

How to use

  1. Configure your flex container

    Use the dropdowns to choose flex-direction, justify-content, align-items, and flex-wrap, and drag the Gap slider. The live preview updates instantly.

  2. Use a preset to get started quickly

    Click a preset chip — Centered, Space between nav, Vertical stack, or Wrapping gallery — to load a common pattern, then fine-tune it.

  3. Copy and use the generated CSS

    Click Copy CSS to copy the complete .flex-container rule and paste it into your stylesheet.

Use cases

Prototyping component layouts

Dial in align/justify/gap visually, then copy the exact CSS into your component instead of guessing property combinations.

Learning Flexbox interactively

See how each property reflows children, which is faster than reading the spec cold.

Debugging a misaligned layout

Reproduce a broken layout in the playground, toggle one property at a time, and find the value that fixes it.

Flex-container properties at a glance

PropertyOptions
flex-directionrow · row-reverse · column · column-reverse
justify-contentflex-start · center · flex-end · space-between · space-around · space-evenly
align-itemsstretch · flex-start · center · flex-end · baseline
flex-wrapnowrap · wrap · wrap-reverse
gap0 – 48 px

Common mistakes

Mistake:Confusing justify-content with align-items.

Fix:justify-content works along the main axis (set by flex-direction); align-items works on the cross axis. Swap them when a layout looks rotated 90° from intent.

Mistake:Setting vertical centering on a row and seeing no effect.

Fix:In a row the cross axis is vertical, so vertical centering uses align-items, not justify-content. Check which axis flex-direction selected.

Mistake:Expecting gap to work without a flex container.

Fix:The gap property applies between flex items only when display: flex (or grid) is set on the parent.

Frequently asked questions

Related guides

Testing Responsive Layouts Across Device Widths

How CSS viewport works vs. device pixels, which breakpoints to test, and why some sites block their own embedding in iframes.

References & standards

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