CSS Flexbox Generator — Build Flex Layouts Visually (Free Tool)

CSS Flexbox is the backbone of modern web layouts. From simple navigation bars to complex responsive grids, Flexbox handles alignment challenges that were difficult or impossible with older CSS techniques.

This guide explains the core flexbox properties, shows you practical layout patterns, and shows you how to use a free online CSS flexbox generator to create and copy flex CSS code instantly.

What is CSS Flexbox?

CSS Flexbox (Flexible Box Layout Module) is a one-dimensional layout system that allows you to control how flex items are arranged, sized, and aligned within a flex container — in either a row or a column.

A flex container is any element with `display: flex` applied. Its direct children automatically become flex items that respond to the flexbox rules you set.

The Core Flexbox Properties (Container)

### flex-direction Defines the main axis of the flex container. - `row` (default): Items flow left to right - `column`: Items stack top to bottom - `row-reverse` / `column-reverse`: Same but reversed

### flex-wrap Controls whether items wrap to new lines when they overflow. - `nowrap` (default): All items stay on one line, potentially overflowing - `wrap`: Items wrap to new rows/columns as needed - `wrap-reverse`: Wrapping happens in reverse direction

### justify-content Distributes items along the **main axis** (horizontal in a row layout). - `flex-start`: Items pack to the start - `flex-end`: Items pack to the end - `center`: Items are centred - `space-between`: Equal gaps between items; no gap at edges - `space-around`: Equal gaps around each item - `space-evenly`: Equal gaps between items and edges

### align-items Aligns items along the **cross axis** (vertical in a row layout). - `stretch` (default): Items stretch to fill the container height - `flex-start`: Items align to the top - `flex-end`: Items align to the bottom - `center`: Items are vertically centred - `baseline`: Items align to their text baseline

### gap Sets spacing between flex items without needing margins. - `gap: 16px` adds 16px between every item in both directions - Cleaner than using margin because gap only applies between items, not at the edges

How to Use the CSS Flexbox Generator

Instead of writing flexbox CSS from memory, use the **[free CSS Flexbox Generator](/tools/flexbox-generator)** on Nexifr:

1. Select your **flex-direction** (row or column) 2. Set **flex-wrap** preference 3. Choose **justify-content** alignment 4. Set **align-items** cross-axis alignment 5. Enter a **gap** value in pixels 6. Copy the generated CSS code directly into your stylesheet

The tool generates the complete CSS declaration block with all properties — ready to paste.

5 Essential Flexbox Patterns

### 1. Centre Anything ```css .container { display: flex; justify-content: center; align-items: center; } ``` The most commonly needed pattern — centres content both horizontally and vertically.

### 2. Horizontal Navigation Bar ```css .navbar { display: flex; flex-direction: row; justify-content: space-between; align-items: center; } ``` Logo on the left, navigation links on the right.

### 3. Responsive Card Row with Wrapping ```css .card-grid { display: flex; flex-wrap: wrap; gap: 16px; } ``` Cards flow left-to-right and wrap to a new row when they run out of space.

### 4. Equal-Width Columns Add `flex: 1` to each child so all columns share available space equally.

### 5. Sidebar + Main Layout Use `flex-direction: row` on the container, then set a fixed width on the sidebar and `flex: 1` on the main area.

Flexbox vs CSS Grid: When to Use Each

**Use Flexbox when**: - You need to lay out items in a single direction (row OR column) - You want items to size themselves based on their content - You need simple centering or distribution

**Use CSS Grid when**: - You need control over both rows AND columns simultaneously - You're building a full page layout - You want items to align to a strict grid

Both can be combined — use Grid for the overall page layout and Flexbox for components within it.

Try the Free CSS Flexbox Generator

Build your flexbox layout visually with Nexifr's **[free CSS Flexbox Generator](/tools/flexbox-generator)** — configure all properties with dropdowns and copy the ready-to-use CSS code in seconds.