What is CSS Flexbox Generator?

CSS Flexbox Generator is a visual tool that helps you build Flexbox layouts without writing code from scratch. Instead of memorizing property names and values, you simply click buttons and adjust controls to see the layout change in real-time.

Perfect for learning: Experiment visually and immediately see the results, making it easy to find the exact layout you need. Once you're satisfied, copy the generated CSS code directly into your project.

Why Use a Visual Flexbox Builder?

Flexbox is one of the most powerful CSS layout systems, but it comes with a learning curve. With properties like justify-content, align-items, flex-wrap, and individual item controls like flex-grow and align-self, it can be hard to remember what each value does.

Who Is This For?

Beginners

Learning CSS Flexbox who want to understand how each property affects the layout

Developers

Who need to quickly prototype a Flexbox layout and grab clean code

Designers

Who want to experiment with layouts before handing off to developers

How to Use

Configure the Container

Use the Container section on the left panel to set the parent flex properties:

flex-direction — Choose how items flow: row (horizontal) or column (vertical)
flex-wrap — Allow items to wrap to the next line or stay on one line
justify-content — Align items along the main axis (e.g., center, space-between)
align-items — Align items along the cross axis (e.g., stretch, center)
align-content — Distribute space between wrapped lines
gap — Set spacing between items (row gap and column gap)

Manage Items

Add or remove flex items using the + and x buttons. You can have up to 12 items. Click on a colored chip or directly on an item in the preview to select it.

Customize Individual Items

When an item is selected, you can adjust its individual properties:

order, flex-grow, flex-shrink, flex-basis — Control item sizing and ordering
align-self — Override the container's align-items for this specific item
width, height, padding — Set explicit dimensions
background, border-radius — Style the item visually

Copy the Code

The CSS code is generated automatically in real-time. Only properties that differ from their default values are included, keeping the output clean. Click Copy to copy the code to your clipboard.

Features

Full Container Control

Configure all six major Flexbox container properties with simple button groups. Each option is labeled with its CSS value, so you learn the syntax while you build.

Individual Item Properties

Select any item to customize its flex behavior independently. Set order to rearrange items, use flex-grow to control how space is distributed, or override alignment with align-self.

Visual Styling Per Item

Beyond flex properties, each item supports visual customization: background color with a color picker, border-radius for rounded corners, custom width/height, and padding adjustments.

Live Preview

Every change updates the preview area instantly. The flex container is displayed with a dashed border, and each item has a distinct color for easy identification. Click items directly in the preview to select them.

Clean Code Generation

The generated CSS only includes properties that differ from their default values. Container properties are grouped under .container, and item-specific overrides get their own .item-N selectors.

Adjustable Container Size

Change the preview container's width (percentage) and height (pixels) to simulate different viewport sizes and test how your layout responds.

Quick Reset: Click the reset button to restore all settings to their defaults: 4 items, no custom properties, and the container at 100% width by 300px height.

Frequently Asked Questions

What is the difference between justify-content and align-items?

justify-content controls alignment along the main axis (horizontal for row, vertical for column). align-items controls alignment along the cross axis (the opposite direction).

Example: In a row layout, justify-content handles horizontal spacing and align-items handles vertical alignment.

When does align-content take effect?

align-content only works when flex-wrap is set to wrap or wrap-reverse AND there are multiple lines of items. It controls how the lines themselves are distributed along the cross axis.

What is the difference between flex-grow and flex-basis?

flex-basis sets the initial size of an item before space distribution. flex-grow determines how much of the remaining space an item should take.

Example: An item with flex-basis: 100px and flex-grow: 1 starts at 100px and expands to fill available space.

Why doesn't my code include all properties?

The generator only outputs properties that differ from their CSS default values. This keeps your code clean and minimal.

Smart optimization: For example, if flex-direction is set to "row" (the default), it won't appear in the output.

Can I use the generated code directly in my project?

Yes. The generated CSS is production-ready. Simply copy it and apply the class names (.container, .item-1, etc.) to your HTML elements. You can rename the selectors to match your project's naming convention.