CSS Flexbox Generator — Build Flex Layouts Visually
Toggle flex-direction, wrap, justify-content, align-items, and alignment visually, then copy the generated CSS into your project. The live preview updates instantly. No upload, no account — runs entirely in your browser.
How to use this tool
- Adjust flexbox properties using the controls.
- See a live preview of the flex container.
- Copy the generated CSS.
flex-direction
flex-wrap
justify-content
align-items
align-content
Preview
Generated CSS
.container {
display: flex;
justify-content: flex-start;
align-items: stretch;
gap: 16px;
}About CSS Flexbox Generator
This tool configures a CSS Flexbox container visually and produces copy-ready code. Button groups let you set the five core flex properties: flex-direction with row, row-reverse, column, and column-reverse; flex-wrap with nowrap, wrap, and wrap-reverse; justify-content across the six common values from flex-start through space-evenly; align-items with stretch, flex-start, flex-end, center, and baseline; and align-content with normal plus the six multi-line distribution values. A slider sets the gap from zero to sixty-four pixels, and a second slider sets how many sample items appear in the preview, from one to eight. A live preview applies your choices to numbered boxes so you can watch the layout respond.
The generated CSS is a tidy .container block, and it is deliberately minimal. It always declares display flex, justify-content, and align-items, but it omits properties that are at their defaults so the output stays clean: flex-direction is written only when it is not row, flex-wrap only when it is not nowrap, align-content only when it is not normal, and gap only when it is greater than zero. The result is that a default configuration produces just the essentials rather than a wall of redundant declarations. A copy button puts the whole block on your clipboard.
The preview faithfully mirrors the active properties, including applying align-content only when it would have an effect, which is when items wrap onto multiple lines. Because the output targets a class named container, you rename the selector to match your markup and the rules apply to that element's direct children. The item count slider affects only the preview and is not part of the generated CSS. Everything runs locally in your browser, so nothing is uploaded.
It is a practical way to nail down a navigation bar, a button row, a centered hero, or a responsive card strip without trial-and-error edits in dev tools, and it doubles as a clear illustration of how justify-content on the main axis differs from align-items on the cross axis. For per-item control such as flex-grow, flex-shrink, or order, add those declarations to the children yourself after pasting the container code.
Frequently Asked Questions
- What CSS does this tool output?
- A .container rule using display flex together with the flexbox properties you select. It always writes justify-content and align-items, and adds the others as needed. You copy the block and paste it into your stylesheet, renaming the selector to match your markup so it applies to that element's children.
- Why are some properties missing from the generated CSS?
- The output is kept minimal by omitting properties left at their defaults. flex-direction appears only when it is not row, flex-wrap only when it is not nowrap, align-content only when it is not normal, and gap only when it is above zero. A default configuration therefore produces a short, clean rule rather than redundant declarations.
- What is the difference between align-items and align-content?
- align-items positions items along the cross axis within a single line and always has an effect. align-content distributes multiple lines of items along the cross axis and only matters when flex-wrap is enabled and the items actually wrap onto more than one line. The preview reflects this, applying align-content only when it would change the layout.
- Which values can I choose for each property?
- flex-direction offers row, row-reverse, column, and column-reverse; flex-wrap offers nowrap, wrap, and wrap-reverse; justify-content offers flex-start, flex-end, center, space-between, space-around, and space-evenly; align-items offers stretch, flex-start, flex-end, center, and baseline; and align-content offers normal plus six distribution values.
- Does the item count slider change the generated code?
- No. The item count only controls how many sample boxes appear in the live preview, from one to eight, so you can see how your settings distribute different numbers of children. It is not part of the CSS the tool outputs.
- Can I set gap, and what is its range?
- Yes. A slider sets the gap from zero to sixty-four pixels in steps of four. When the gap is zero it is left out of the generated CSS, and when it is above zero it is written as a gap declaration in pixels.
- Does it generate per-item properties like flex-grow or order?
- No. The tool configures the flex container only. Item-level properties such as flex-grow, flex-shrink, flex-basis, and order are not produced. Add those declarations to the individual child elements yourself after pasting in the container rule.
- Is my configuration sent anywhere?
- No. The CSS is generated and previewed entirely in your browser, so nothing you configure is uploaded to a server.
Embed this tool on your site
Free. One line of HTML — the tool runs in your visitor's browser, no data sent to anyone.
<iframe src="https://brevio.pro/embed/css-flexbox-generator" width="100%" height="600" loading="lazy" style="border:1px solid #e5e5e5;border-radius:8px" title="CSS Flexbox Generator — brevio"></iframe> <p style="font:12px/1.4 sans-serif"><a href="https://brevio.pro/tools/css-flexbox-generator">CSS Flexbox Generator</a> by <a href="https://brevio.pro">brevio</a></p>