Local Tools Online

CSS Flexbox Generator

justify-content versus align-items, flex-direction: row versus column, what flex: 1 1 auto actually does when you have three sibling items competing for space — Flexbox has a small number of properties that interact in ways that aren’t obvious until you see them move. The CSS Flexbox Generator gives you a live container with real, draggable child boxes, so you can toggle direction, wrapping, and alignment and watch the layout respond instantly, then copy the CSS once it looks right.

Why local processing matters here

Flexbox properties themselves aren’t sensitive, but the practical use case almost always involves real interface work — navbar layouts, form field arrangements, card components — built while looking at, or copy-pasting alongside, actual product markup that may not be public yet. There’s no reliable way for a server-side tool to promise that context isn’t captured somewhere along the way. Because everything here runs in the browser, the layout you’re testing and anything else visible in that session stays local, with nothing sent anywhere to get a working answer.

How to use it

  1. Set the container’s flex-direction (row or column) and see how the child items rearrange immediately.
  2. Toggle flex-wrap on if you want items to wrap to a new line/column once they run out of space, rather than shrinking or overflowing.
  3. Adjust justify-content to control spacing along the main axis — space between items, centered, pushed to the edges, or evenly distributed.
  4. Adjust align-items to control alignment along the cross axis, useful for vertically centering items in a row layout without extra markup.
  5. Click individual child items to set their own flex-grow, flex-shrink, and flex-basis values if some items need to take up more or less space than their siblings.
  6. Copy the generated CSS for both the container and any individually-adjusted children once the layout matches what you need.

Common situations this solves

  • Building a navbar where the logo sits left, nav links sit right, and everything stays vertically centered regardless of content height.
  • Getting form fields and their labels to align consistently when field widths vary.
  • Centering a single element both horizontally and vertically without resorting to absolute positioning tricks.
  • Making a row of cards distribute evenly across the full container width regardless of how many cards are present.
  • Understanding why an existing flex layout is behaving unexpectedly, by rebuilding a simplified version here to isolate the property causing it.

FAQ

Why won’t my flex item shrink below its content size? 

By default, flex-shrink still respects the item’s minimum content size unless min-width: 0 (or min-height: 0 for column layouts) is explicitly set — this is one of the most common Flexbox surprises, and it’s worth testing directly in the generator to see the effect.

What’s the actual difference between flex: 1 and flex: 1 1 auto? 

flex: 1 is shorthand for flex: 1 1 0%, meaning items grow and shrink from a zero basis, ignoring their content size when distributing space. flex: 1 1 auto starts from the item’s natural content size instead, which produces noticeably different results when items have different amounts of content — toggling between the two in the generator makes the difference immediately visible.

Should I use Flexbox or Grid for a layout with rows and columns that need to line up together? 

Grid generally handles that case more cleanly since it’s built for two-dimensional alignment. The CSS Grid Generator is worth trying side by side if your layout needs items in one row to align with items in another.

Why do my flex items not wrap even though I set flex-wrap: wrap? 

This usually means the container doesn’t have a constrained width forcing items to run out of room — flex-wrap only kicks in once items actually can’t fit on one line, so check that the container has a fixed or max width.

Can I get the Tailwind equivalent of a layout I build here? 

Yes — copy the generated CSS and run it through the CSS → Tailwind Converter, which maps standard flex properties to their corresponding Tailwind utility classes (flex, justify-between, items-center, and so on).

Does the generator handle gap for spacing between flex items? 

Yes — gap works on flex containers in all current browsers and is generally cleaner than margin-based spacing since it doesn’t add extra space at the container edges.