How to use the CSS Flexbox Generator
1. Adjust the Flexbox properties using the dropdowns — the preview updates in real time.
2. Change the number of items to test how the layout behaves with different content counts.
3. Copy the generated CSS and apply it to your container element.
What is it?
CSS Flexbox (Flexible Box Layout) is a one-dimensional layout system for arranging items in rows or columns with powerful alignment and distribution capabilities. It's the most widely used layout method for navigation bars, card grids, form layouts, and component internals.
The four core properties: flex-direction sets the main axis (row or column), justify-content controls alignment along the main axis (left/right or space distribution), align-items controls alignment on the cross axis (top/bottom), and flex-wrap controls whether items wrap to new lines. Together these six properties handle the vast majority of real-world layout needs without complex calculations.
Example
Direction: Row · justify-content: center · align-items: center · flex-wrap: wrap
.container {
display: flex;
flex-direction: row;
justify-content: center;
align-items: center;
flex-wrap: wrap;
}This is the standard centering trick in CSS. Add gap: 1rem for spacing between flex children.
Benefits
Learn flexbox by seeing the effect of each property in real time
Change justify-content, align-items, flex-direction, and flex-wrap and see the layout update immediately — faster than reading docs.
Generate complete flexbox CSS for common layout patterns
Navigation bars, card grids, vertically centred content — common patterns are one-click presets with editable output.
Debug flexbox alignment by testing property combinations
Find the exact combination of flex properties that produces the layout you want before writing it into your stylesheet.
Output includes both container and item properties
The generated CSS covers display:flex, justify-content, align-items on the container and flex-grow, flex-shrink on items.
Frequently asked questions
What is the difference between justify-content and align-items?
justify-content controls alignment along the main axis (horizontal in row mode, vertical in column mode). align-items controls alignment on the cross axis (vertical in row mode, horizontal in column mode). Think: justify = main direction, align = perpendicular direction.
When should I use Flexbox vs Grid?
Use Flexbox for one-dimensional layouts where items flow in a single row or column — navigation bars, button groups, card lists. Use Grid for two-dimensional layouts where you need to control both rows and columns simultaneously — page layouts, image galleries, dashboards.
What does flex-wrap do?
By default (nowrap), flex items shrink to fit in one line. With wrap, items that don't fit spill onto new lines. This is essential for responsive layouts — items can be full-width on mobile and flow into columns on wider screens.