Why this matters
CSS Grid is the most powerful layout system available in CSS, yet the `grid-template-areas` syntax — the most readable way to define complex layouts — remains intimidating to write by hand. A single typo, like a non-rectangular area or a missing cell, causes the entire areas block to be ignored by the browser. This means you can stare at your CSS for ten minutes before realizing the problem is a stray dot or an L-shaped region that the spec forbids.
This generator turns that abstract syntax into a visual painting exercise. You set columns and rows with sliders, pick an area name from a palette, and click cells to paint them. The tool validates every area for rectangularity in real time, so broken layouts are caught before you copy any code. Four column-unit options — `1fr`, `auto`, `minmax(0, 1fr)`, and fixed pixel widths — cover the vast majority of real-world responsive layouts without requiring manual CSS editing after export.
Controls and output reference
| Control | Function | Output effect |
|---|---|---|
| Column/row sliders | Set grid dimensions | `grid-template-columns` and `grid-template-rows` |
| Gap slider | Spacing between cells | `gap: Npx` |
| Column unit | Width strategy | `1fr`, `auto`, `minmax(0, 1fr)`, or `80px` |
| Area palette | Six named areas | header, nav, main, sidebar, ads, footer |
| Cell click | Paint or clear | Adds/removes area name from `grid-template-areas` |
| Rectangle validator | Real-time check | Warns if any area is non-rectangular |
How to use it
Set the number of columns and rows using the sliders to match your desired layout structure.
Adjust the gap value and select a column unit — use `1fr` for equal-width fluid columns or `minmax(0, 1fr)` to prevent long content from blowing out the grid.
Select an area name from the palette (header, nav, main, sidebar, ads, footer) and click cells to paint that area.
Click a painted cell again to clear it, or use the Clear button to wipe the entire grid.
Copy the generated CSS once the validator confirms all areas are rectangular.
Testing your result
Paste the copied CSS into a blank HTML file with a few `div` elements carrying the area names as class names, and open it in your browser. Verify that the layout matches what you painted on the grid. Resize the browser window to confirm responsive behavior — `1fr` columns should shrink and grow proportionally, while `minmax(0, 1fr)` columns should contain overflow. Test with realistic content lengths including long words and wide images to ensure nothing breaks the grid.
Common mistakes
Creating L-shaped or disconnected areas, which the validator will flag because `grid-template-areas` requires every named region to form a single filled rectangle.
Using `1fr` when you have long unbroken strings (like URLs or code snippets) that can force the column wider than intended — switch to `minmax(0, 1fr)` instead.
Forgetting that the six palette names are presets, not limits — you can rename areas in the copied CSS to any valid CSS identifier.
Leaving gaps (unpainted cells represented by dots) inside what you intended as a single area, which splits it into separate regions and breaks the rectangle rule.
Edge cases and options
The gap slider outputs values in pixels for clarity. If you prefer rem units, divide by 16 — for example, a 12px gap becomes roughly 0.75rem. The six area names on the palette cover common page layouts, but `grid-template-areas` accepts any valid CSS identifier. After copying, you can rename 'ads' to 'aside' or 'main' to 'content' directly in your stylesheet. The tool generates top-level grid CSS; for subgrid support, you would manually add `grid-template-columns: subgrid` to a child element within the parent grid.
Real-world use cases
Front-end developers prototyping page layouts without writing CSS from scratch, then copying the validated output into their component library.
Designers who want to communicate exact grid structures to developers by sharing a visual layout alongside the CSS.
Students learning CSS Grid who benefit from seeing how cell-by-cell painting translates directly to the template-areas syntax.
Teams establishing a grid system for a design system and needing a quick way to experiment with column and row configurations.
Frequently asked questions
Q: Why do my areas need to be rectangular?
A: CSS grid-template-areas requires each named area to form a single rectangle with no L-shapes or holes. The validator warns you when this rule is violated, and the CSS skips the areas block until you fix it.
Q: What does the column unit selector do?
A: It controls grid-template-columns: 1fr makes equal fluid columns, auto sizes to content, minmax(0, 1fr) prevents blowout from long content, and 80px uses fixed-width columns.
Q: Can I use more than 6 area names?
A: The palette ships with six common names. For more, paint cells then rename them in the copied CSS — grid-template-areas accepts any valid identifier.
Q: Does this work for subgrid?
A: The output is for top-level grid layout. Subgrid support depends on the parent grid; you would add grid-template-columns: subgrid to a child manually.
Q: Are gaps in px or rem?
A: The gap slider outputs px for clarity. Convert to rem by dividing by 16 — for example, 12px is approximately 0.75rem.
Q: Can I set different column widths per column?
A: Not in this version — the unit selector applies uniformly. For mixed column widths, copy the base CSS and edit grid-template-columns manually.
Start using it now
Try the CSS Grid Generator tool. See also Flexbox Playground, Media Query Generator, and Box Shadow Generator.
