CSS Flexbox Generator
Build CSS flexbox layouts visually — set all container properties with live preview, override individual item properties, and start from preset patterns (navbar, sidebar, card grid, centering). Copy complete CSS in one click.
CSS Flexbox Generator Tool
Preset layout patterns and per-item overrides — features most flexbox generators skip
Most flexbox tools give you sliders for container properties and nothing else. This generator adds six preset layout patterns that instantly set all values to match real-world use cases, plus per-item controls that let you override flex-grow, flex-basis, align-self and order on any individual child element.
How to generate CSS flexbox code
How this compares to other CSS flexbox generators
| Feature | LazyTools | CSS Portal | Loading.io | Flexy Boxes |
|---|---|---|---|---|
| Preset layout patterns | Yes — 6 presets | No | No | No |
| Per-item override controls | Yes — all item props | Partial | No | Partial |
| All 7 container properties | Yes | Yes | Partial | Yes |
| Responsive width preview | Yes — 3 widths | No | No | No |
| Copy HTML structure | Yes | No | No | No |
| Add / remove items | Yes | Yes | No | Yes |
| Live preview | Yes | Yes | Yes | Yes |
CSS flexbox property quick reference
| Property | Applied to | Values & effect |
|---|---|---|
| display | Container | flex · inline-flex — activates flexbox on the element |
| flex-direction | Container | row · row-reverse · column · column-reverse — sets main axis |
| flex-wrap | Container | nowrap · wrap · wrap-reverse — controls whether items wrap |
| justify-content | Container | flex-start · center · flex-end · space-between · space-around · space-evenly |
| align-items | Container | stretch · flex-start · center · flex-end · baseline — cross-axis per row |
| align-content | Container | stretch · flex-start · center · flex-end · space-between — multi-row cross axis |
| gap | Container | Any length — space between items (replaces margin hacks) |
| flex-grow | Item | 0–∞ — share of spare space the item claims |
| flex-shrink | Item | 0–∞ — how much the item gives up when space is short |
| flex-basis | Item | auto · 0 · length/% — starting size before grow/shrink |
| align-self | Item | auto · flex-start · center · flex-end · stretch — overrides align-items |
| order | Item | Integer — visual position (default 0, lower = earlier) |
CSS Flexbox — A Complete Guide for Developers
CSS Flexbox (Flexible Box Layout) transformed how developers build one-dimensional layouts. Before flexbox, centering an element vertically required negative margins, table-cell hacks, or absolute positioning. Equal-height columns needed JavaScript. Distributing space evenly required careful float arithmetic. Flexbox solved all of these with a handful of intuitive properties that describe the intention of the layout rather than the mechanism.
CSS flexbox generator with live preview free
A visual flexbox generator lets you manipulate all the container and item properties simultaneously and see the effect in real time — something that is nearly impossible to build intuition for by reading the specification alone. The most useful generators show not just the container properties but also the per-item overrides, since real layouts almost always need at least one item to behave differently from the rest: a growing main content area, a fixed sidebar, a differently-aligned call-to-action button.
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Understanding the two axes is the foundation of flexbox. The main axis runs in the direction set by flex-direction: horizontal when flex-direction is row, vertical when it is column. justify-content controls alignment along the main axis — it determines how spare space is distributed between items, whether they cluster at the start, the end, the centre, or are spread evenly. The cross axis is perpendicular to the main axis. align-items controls how items are positioned along the cross axis within a single row or column. When items wrap to multiple lines, align-content controls how those lines are distributed along the cross axis as a group.
Visual flexbox layout builder online
Flexbox presets are patterns where a specific combination of container and item properties produces a named real-world layout. The navbar preset uses flex-direction:row, justify-content:space-between, align-items:center — logo sits at the left edge, navigation links at the right, everything vertically centred. The sidebar + content preset uses two items with different flex-basis values: the sidebar gets a fixed width (e.g. 250px) with flex-shrink:0 so it never squeezes, and the main content gets flex-grow:1 so it consumes all remaining space. The card grid preset uses flex-wrap:wrap with items set to a percentage flex-basis, creating a responsive multi-column grid without any media queries.
Flexbox playground with code generator
The three flex item shorthand properties — flex-grow, flex-shrink, and flex-basis — determine how an item responds to available space. flex-basis sets the starting size before any distribution happens. flex-grow determines how much of the leftover space an item claims relative to other items (0 means it takes no extra space; 1 means it takes an equal share; 2 means it takes twice as much as an item with flex-grow:1). flex-shrink determines how much the item gives up when the container is too small (0 means it refuses to shrink; 1 means it shrinks proportionally). The shorthand flex:1 is equivalent to flex-grow:1; flex-shrink:1; flex-basis:0 — a common pattern for items that should share available space equally.
CSS flexbox navbar generator
The flexbox navbar is one of the most common layout patterns in modern web development. The container is display:flex with justify-content:space-between so the logo and the nav links sit at opposite ends of the row. align-items:center vertically centres all children regardless of their height. The nav links group is itself a flex container with gap for spacing between links. The entire navbar is typically 60–80px tall with padding for visual breathing room. On mobile, the flex-direction switches to column via a media query, stacking the logo above the links. This generator lets you build both states visually and copy the CSS for each.
Responsive layout flexbox generator
Responsive flexbox layouts use flex-wrap:wrap combined with percentage-based flex-basis values on items to create multi-column layouts that reflow gracefully as the viewport narrows. A three-column card grid uses items with flex-basis:calc(33.333% - 16px) (subtracting the gap). At a medium breakpoint, the basis switches to calc(50% - 8px) for two columns. At mobile, it switches to 100% for a single column. The preview width toggle in this generator lets you see all three states without resizing your browser — switch to 480px to immediately see which items wrap and which need their flex-basis adjusted.