Flexbox and Grid Generator
Lay out a row, a column, or a full grid visually and watch the CSS update as you go. Switch between flexbox and CSS grid, set the direction, alignment, wrapping, column and row counts, and the gap, then read the result on a live preview made of numbered boxes that behave exactly like real elements. Instead of remembering whether centering needs justify-content or align-items, you change a control and see the boxes move. The output is plain, copy-ready CSS for a container class, computed entirely in the browser, so you can drop it straight into a stylesheet, a component, or a Tailwind layer without anything leaving the page.
- Switch between flexbox and CSS grid without losing the layout you were shaping
- Control direction, justify, align, wrapping, columns, rows, and gap with instant feedback
- A live preview of numbered boxes shows exactly how each property moves real elements
- Copy clean CSS for a container class, ready for stylesheets, components, or Tailwind
- Everything is computed in the browser, so nothing about your layout is uploaded
.container {
display: flex;
flex-direction: row;
flex-wrap: nowrap;
justify-content: flex-start;
align-items: stretch;
gap: 12px;
}<div class="container"> <div class="item">1</div> <div class="item">2</div> <div class="item">3</div> <div class="item">4</div> <div class="item">5</div> </div>
Overview
Bring the two CSS layout systems people reach for every day into one panel, so you can pick the right one for the job and tune it by eye instead of guessing property names in a stylesheet.
- 01
Flexbox and grid in one place
Toggle between flexbox for one-dimensional rows and columns and CSS grid for two-dimensional layouts, keeping the same gap and item count as you compare them.
- 02
Every alignment property exposed
Direction, justify-content, align-items, wrapping, and align-content for flex, plus columns, rows, auto-flow, justify-items, and align-items for grid, all as plain controls.
- 03
A preview that behaves like real elements
Numbered boxes respond to each property the same way real children do, so you can tell at a glance whether items center, spread, stretch, or wrap.
- 04
Sensible starting presets
Common recipes such as a centered row, a space-between bar, a vertical stack, a wrapping row, and grids are one click away, ready to refine.
- 05
Clean, copy-ready output
The CSS targets a single container class and the matching HTML structure is available beside it, so both pieces are easy to paste into a stylesheet, component, or prototype.
- 06
Local and private by default
Every preview and every line of generated CSS is computed in the browser, which keeps unreleased layouts and internal UI off any server.
How to use
Go from an empty container to working layout CSS in a few steps, whether you are matching a design or learning how the properties relate.
- 01
Choose flexbox for a single row or column, or grid for a layout with both columns and rows.
- 02
Pick a preset close to what you want, or start from the default and adjust controls one at a time.
- 03
Set the main properties: direction and justify or align for flex, or column and row counts for grid.
- 04
Tune the gap and the number of items until the preview matches the spacing and density you need.
- 05
Read the layout on the preview boxes, then copy the container CSS into your stylesheet or component.
Details
Flexbox and grid cover almost every modern layout, so a visual editor for them needs to map cleanly onto the real CSS rather than hide it behind invented names.
- Flexbox controls cover flex-direction, flex-wrap, justify-content, align-items, and align-content
- Grid controls cover template columns and rows with repeat and 1fr tracks, grid-auto-flow, justify-items, and align-items
- A shared gap and item count let you compare the same content under flexbox and under grid
- The preview uses real flex and grid containers, so alignment, wrapping, and distribution behave authentically
- align-content appears only when wrapping is on, mirroring when the property actually has an effect
- Presets cover centering, space-between bars, vertical stacks, wrapping rows, and multi-column grids
- A randomize action explores unfamiliar property combinations to build intuition quickly
- Output includes clean container CSS and a matching HTML structure, easy to read and adapt
- Generated CSS pastes directly into stylesheets, CSS modules, component styles, or Tailwind layers
- All computation runs locally in the browser, so layouts for unreleased work stay private
Use cases
Layout questions come up constantly in frontend work, and most of them are really questions about which flex or grid property to reach for. Seeing the answer move on screen is faster than reading another reference.
-
Centering content
Confirm which combination of justify-content and align-items centers a box both horizontally and vertically, instead of guessing between the two.
-
Navigation bars
Push a logo to one side and links to the other with space-between, a pattern that shows up in almost every header and toolbar.
-
Card and product grids
Lay out cards in even columns with consistent gaps using grid, then adjust column count to see how the layout reflows.
-
Responsive wrapping rows
Watch how flex-wrap and align-content arrange tags, chips, or buttons when they no longer fit on a single line.
-
Forms and stacked fields
Stack labels and inputs in a column with even spacing, a common flex layout for forms, settings panels, and sidebars.
-
Galleries and dashboards
Arrange thumbnails or widgets into a tidy grid and judge spacing and density before wiring up the real content.
-
Learning flex and grid
Change one property at a time and watch the boxes respond, which builds intuition for how the layout systems actually work.
-
Prototyping layouts quickly
Sketch the structure of a page or component visually and copy the container CSS as a starting point for real markup.
See also
Once the layout is in place, give surfaces depth and elevation with Box Shadow Generator , and when a section needs a richer background, design it alongside the layout using Gradient Generator so spacing, depth, and color stay consistent across the component.
Best practices
Flexbox and grid are forgiving to experiment with but easy to misuse, so a few habits keep generated layouts robust across screens and content.
- Reach for flexbox when content flows in one direction and for grid when you need rows and columns together.
- Prefer the gap property over margins on children, since it spaces items evenly without edge-case margins to clean up.
- Use justify-content for spacing along the main axis and align-items for the cross axis, and check which is which in the preview.
- Let content and available space drive wrapping rather than hard-coding breakpoints for every small change.
- For grid, repeat with 1fr keeps columns even, while explicit track sizes are better when widths must differ.
- Test layouts with both few and many items, because distribution properties behave differently as content grows.
- Promote recurring layout recipes into reusable classes or components instead of repeating the same properties everywhere.
- Verify the result at real breakpoints in the project, since the preview shows the mechanics but not your exact container width.
Limitations
This tool focuses on the core container properties that shape a layout, so a few related areas are intentionally out of scope.
- It generates container CSS. Per-item rules such as flex-grow, flex-basis, order, and grid column or row spans are not produced here.
- Grid tracks use repeat with 1fr. Named lines, grid-template-areas, and mixed fixed and fractional tracks need hand editing.
- The preview uses a fixed-height container, so layouts that depend on real content height should be confirmed in the project.
- Responsive behavior across breakpoints depends on your actual container widths and media or container queries.
- Browser differences are minimal for modern flex and grid, but very old browsers may need fallbacks this tool does not add.
- It does not output full HTML structure, only the CSS for a container that you apply to your own markup.
FAQ
Questions that come up most often when choosing between flexbox and grid and when translating a layout idea into working CSS.
Should I use flexbox or grid?
Use flexbox when content flows in a single direction, such as a row of buttons or a column of fields. Use grid when you need to control both columns and rows at once, such as a card gallery or a dashboard.
Is the generated CSS ready for production?
Yes. The output is standard CSS for a container class and can be pasted into stylesheets, CSS modules, component styles, or a Tailwind layer without changes.
How do I center something both ways?
In flexbox, set justify-content and align-items to center. In grid, set justify-items and align-items to center. The preview confirms it as soon as you change the controls.
Why does align-content only appear sometimes?
align-content only affects a flex container when items wrap onto more than one line, so the control appears once you turn wrapping on, which mirrors when the property actually does anything.
Does it generate per-item properties?
No. This tool focuses on container properties. Per-item rules like flex-grow, flex-basis, order, and grid spans are layout details you add to individual children afterward.
Can I use the output with Tailwind?
Yes. You can paste the CSS into a custom layer or component class, or use it as a reference for the equivalent flex and grid utility classes.
What does 1fr mean in the grid output?
A fr unit is a fraction of the free space in the grid. repeat(3, 1fr) creates three columns that each take an equal share of the available width.
Is my layout uploaded while I edit?
No. All preview rendering and CSS generation happen locally in the browser, which makes the tool safe for unreleased product UI and confidential design work.
Related tools
Layout is the frame that everything else sits inside. Once the structure is set, move on to depth and background so the component reads as a finished surface, not just an arrangement of boxes.