CSS Flexbox Generator Online Free
The free CSS Flexbox Generator lets you build flex layouts without writing code first. Configure the container and each individual item, watch the live preview update instantly, then copy the generated CSS directly into your project.
What the CSS Flexbox Generator Does
The tool provides a visual interface for every core Flexbox property. On the left, a controls panel lets you set all container properties — flex-direction,flex-wrap, justify-content, align-items,align-content, and gap. Below that, each flex item has its own settings for flex-grow, flex-shrink, flex-basis,align-self, and order.
On the right, a live preview panel shows coloured boxes arranged inside a real flex container that updates as you change any property. Below the preview, the CSS Output panel shows the complete, ready-to-use stylesheet — one .container rule and one rule per item — with a Copy CSS button.
How to Use the Flexbox Generator
- Open the CSS Flexbox Generator. Three default items appear in a row layout.
- Use the Container dropdowns to set the direction, wrap behaviour, and alignment properties. The preview updates immediately.
- Adjust row-gap and column-gap to set spacing between items.
- In the Items section, set
flex-grow,flex-shrink, andflex-basisper item to control how each one sizes relative to the others. Usealign-selfto override the container'salign-itemsfor a specific item. - Click + Add to add more items (up to 8) or the × button to remove one.
- Click Copy CSS to copy the generated stylesheet to your clipboard.
Container Properties Reference
| Property | What It Controls | Common Values |
|---|---|---|
flex-direction | The main axis — which direction items flow | row, column, row-reverse, column-reverse |
flex-wrap | Whether items wrap to new lines when they overflow | nowrap, wrap, wrap-reverse |
justify-content | Alignment along the main axis | flex-start, center, space-between, space-evenly |
align-items | Alignment along the cross axis for a single line | stretch, flex-start, center, baseline |
align-content | Alignment of multiple lines when wrapping is active | stretch, center, space-between |
gap | Space between items (row-gap and column-gap) | 8px, 16px, 1rem |
Item Properties Reference
| Property | What It Controls | Default |
|---|---|---|
flex-grow | How much of remaining space this item claims relative to others | 0 (does not grow) |
flex-shrink | How much this item shrinks relative to others when space is tight | 1 (shrinks proportionally) |
flex-basis | The item's initial size before remaining space is distributed | auto (uses content size) |
align-self | Overrides the container's align-items for this item only | auto (inherits from container) |
order | Visual display order without changing HTML source order | 0 |
Common Flexbox Patterns
Equal-width columns
Set flex-grow: 1, flex-shrink: 1, and flex-basis: 0on every item. This makes all items share the available space equally regardless of their content size. The shorthand is flex: 1.
Sticky footer
On the page wrapper, set flex-direction: column and min-height: 100vh. Give the main content area flex-grow: 1. The footer then stays at the bottom even on short pages, because the main content stretches to fill the remaining space.
Centring anything
On the container set justify-content: center and align-items: center. The child element is perfectly centred regardless of its size or the container's dimensions. This is the most common use of Flexbox for single-element alignment.
Responsive card row
Set flex-wrap: wrap on the container and flex-basis: 220px withflex-grow: 1 on the items. Cards fill the row and wrap naturally as the viewport narrows — no media queries needed.
Reordering without changing HTML
Use the order property on individual items to change their visual position independently of DOM order. This is useful for mobile layouts where a sidebar needs to appear after the main content in the source but before it visually.
Flexbox vs CSS Grid
Flexbox and Grid solve different problems. Flexbox is one-dimensional — it arranges items along a single row or column and distributes leftover space within that axis. Grid is two-dimensional — it controls both rows and columns simultaneously and allows precise placement into named areas.
Use Flexbox for navigation bars, button groups, card rows, and any layout where the number of items is dynamic. Use the CSS Gradient Generator or the CSS Box Shadow Generator alongside Flexbox to handle colour and depth once the layout is set.
Common Questions
Why isn't align-content doing anything?
align-content only applies when there are multiple lines of flex items — i.e. when flex-wrap is set to wrap or wrap-reverse and the items actually overflow onto a second line. With nowrap, all items stay on one line so align-content has no effect.
What is the difference between flex-basis: auto and flex-basis: 0?
With auto, each item starts at its natural content size before remaining space is distributed. With 0, all items start at zero width and the available space is divided purely by their flex-grow ratios — making it easier to create truly equal-width columns unaffected by content length.
Can I use Flexbox for the whole page layout?
Yes, though CSS Grid is often a better fit for full-page two-dimensional layouts. Flexbox works well for page-level layouts when items flow naturally in one direction — for example a vertical stack of header, main, and footer. For more complex row-and-column arrangements, Grid gives you finer control.
Does the generated CSS work in all browsers?
Flexbox has full support in all modern browsers (Chrome, Firefox, Safari, Edge) and has since around 2016. The generated CSS uses standard syntax with no vendor prefixes — you do not need -webkit- or -ms- prefixes for any of the properties in the output.
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