Flexbox Playground
Learn and generate CSS Flexbox code visually.
Last reviewed by the Radiatus Cloud team
Flex Container
display: flex;
flex-direction: row;
justify-content: flex-start;
align-items: stretch;
gap: 10px;
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See Flexbox behave
Flexbox controls how items lay out along a single direction, and its properties interact in ways that are genuinely hard to predict from the names alone. This playground lets you adjust direction, alignment and wrapping visually and generates the matching CSS, so you learn Flexbox by watching the items move and leave with code you can actually use. It turns an abstract set of rules into something you understand by seeing rather than by memorising.
The properties that confuse everyone
The classic confusion is between justify-content and align-items, specifically which axis each one affects, and the confusion deepens because it flips the moment you change the flex direction from row to column. Seeing the items slide as you toggle each property is what finally makes the main-axis and cross-axis distinction stick in your mind for good. That understanding, once it becomes visual and intuitive, transfers to every layout you build afterwards without having to look it up.
Learn once, apply everywhere
It runs entirely in your browser, so nothing you enter is uploaded and the generated code is yours to paste straight into a project. Because it works client-side, you can iterate freely, regenerating as often as you like without a round trip to any server.
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Frequently Asked Questions
What does Flexbox do?
It lays out items along a single direction, a row or a column, and controls how they align, space out and wrap. It is the standard tool for one-dimensional layout.
Why do justify-content and align-items confuse people?
Because which axis each affects depends on the flex direction, and it swaps when you change from row to column. Seeing it move makes the distinction clear.
What is the main axis?
The direction items flow in, set by flex-direction. justify-content aligns along it; align-items aligns across it, on the cross axis.
Does it generate usable CSS?
Yes. The playground outputs the Flexbox CSS for the layout you build, ready to paste into a project.
Is my work uploaded?
No. The playground runs entirely in your browser.
Privacy & Security
Generated locally.
About This Tool
This tool runs entirely in your browser. No data is sent to any server, ensuring complete privacy. Simply use the interface above to get started — no registration or login required.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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DesignConvert colours between HEX, RGB, HSL, HWB and OKLCH, with alpha support. Runs in your browser and shows the live swatch for each format.
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DesignCheck foreground and background colour contrast against WCAG thresholds, with the rules for text size, UI components and states.
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DesignGenerate a modular type scale from a base size and ratio, with fluid clamp() values for responsive layouts.