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Flexbox Generator
Set flexbox properties visually with a live preview and copy the CSS.
Updated July 13, 2026
How to use the flexbox generator
- 1Choose flex-direction, justify-content, align-items, and wrap.
- 2Adjust the gap and the number of preview items.
- 3Watch the preview reflow to match.
- 4Copy the CSS onto your flex container.
Common uses
- Centering content vertically and horizontally
- Building a responsive nav bar or toolbar
- Learning what each flexbox property does
- Prototyping a layout before writing code
Frequently asked questions
What's the difference between justify-content and align-items?
justify-content aligns items along the main axis (the direction set by flex-direction), while align-items aligns them along the cross axis. In a row, justify-content is horizontal and align-items is vertical; switch to a column and they swap. The live preview makes the difference obvious.
When should I use Flexbox vs Grid?
Flexbox is one-dimensional — a single row or column of items that can wrap. CSS Grid is two-dimensional — rows and columns together. Use Flexbox for toolbars, nav bars, and centering; use Grid for page layouts and card grids. Many designs combine both.
Does the copied CSS go on the container or the items?
On the container — the element that wraps the items. The generated '.container' rule includes display: flex plus the properties you set. The child items need no special CSS to participate, though you can add flex-grow or flex-basis to them separately.
About this tool
The Flexbox generator turns the CSS flexbox properties into visual controls with a live, reflowing preview. Adjust flex-direction, justify-content, align-items, flex-wrap, and gap, add or remove preview items, and watch the layout update instantly — then copy clean CSS for the container. It's the fastest way to remember which property does what: justify-content aligns along the main axis, align-items across it, and flex-direction decides which axis is which. For two-dimensional layouts, the CSS Grid generator is the companion. Everything runs in your browser.
Like most tools on UtilityBase, the flexbox generator runs entirely in your browser — nothing you enter is uploaded or stored on a server. It's free to use with no account required. Browse more developer tools here.
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