Flexbox Generator

What this tool does

Flexbox Generator is an interactive playground covering every major flex container property, direction, wrap, justify-content, align-items and gap, with a live visual preview showing exactly how a set of flex items responds, and the resulting container CSS ready to copy.

Flexbox’s property names (justify-content vs align-items, which axis each one actually controls) are notoriously easy to mix up without a visual reference showing the effect directly.

This playground lets you adjust every major flex container property, direction, wrap, justify-content, align-items and gap, with a live preview of a set of flex items responding immediately, so the effect of each property is unmistakable.

How to use Flexbox Generator

1. Set the flex-direction (row or column, with optional reverse).
2. Adjust justify-content and align-items to control item positioning.
3. Set the gap and number of preview items.
4. Copy the resulting container CSS.

Tips for better results

• justify-content controls alignment along the main axis (the direction items flow in), while align-items controls alignment along the cross axis (perpendicular to that), switching flex-direction between row and column swaps which visual direction each one actually affects.
• flex-wrap: wrap lets items that don’t fit on one line flow onto additional lines, rather than overflowing or shrinking indefinitely to fit a single row.
• The gap property is a simpler modern alternative to adding margins between flex items, it adds spacing only between items, never on the outer edges of the container.
• This playground covers the container’s own properties; individual flex items can additionally be given their own flex-grow, flex-shrink or flex-basis values for finer per-item control not shown here.

Common use cases

• Learning how flexbox’s alignment properties behave by experimenting visually rather than reading documentation alone.
• Quickly prototyping a navigation bar, button group, or card layout’s alignment before writing real code.
• Generating the exact container CSS for a specific flex layout you’ve visually dialed in.
• Debugging why an existing flex layout isn’t aligning as expected by comparing it against a known-working configuration here.

Common mistakes to avoid

• Confusing which property controls which axis; remember justify-content is always the main axis (the flex-direction itself), align-items is always the cross axis (perpendicular to it).
• Forgetting flex-wrap defaults to nowrap, meaning items will shrink or overflow rather than wrap onto a new line unless wrap is explicitly set.
• Expecting this container-level playground to cover per-item properties (flex-grow, flex-basis, order); those are set individually on each flex item, not on the container, and aren’t part of this tool’s scope.