Free Online CSS Grid Layout Builder & Code Generator

Overview

A comprehensive, browser-based visual utility that allows web designers and developers to interactively draw CSS Grid layouts. Users can define rows, columns, gaps, and grid-template-areas on a visual canvas, while simultaneously generating the corresponding production-ready CSS and HTML code.

Core Features

• Interactive Canvas: A drag-to-resize grid visualizer where users can click-and-drag to create new grid areas.
• Real-time Code Sync: A side-by-side view where the CSS and HTML automatically update as the visual grid is manipulated.
• Gap Controls: Precise inputs for row-gap and column-gap in various units (px, em, rem, %).
• Responsive Preview: Toggle between desktop, tablet, and mobile views to see how the grid behaves.
• One-Click Export: A button to copy the generated clean, indented CSS/HTML code to the clipboard.
• Semantic HTML Generator: Automatically generates the <div class="grid-container"> and child items with appropriate class names based on the visual layout.

User Interface (UI) Layout

• Header: Title of the tool and a toolbar containing global actions (Reset, Copy All, View Documentation).
• Sidebar (Left): Control panel containing input fields for Grid Columns/Rows (repeat counts, minmax values) and Gap settings.
• Main Canvas (Center): The primary interaction area. A clean, white canvas with a subtle dot grid background. Users draw rectangles to define grid areas.
• Output Pane (Bottom/Right): A dedicated section displaying syntax-highlighted code. The code updates instantly upon canvas interaction.

Design System & Aesthetics

• Color Palette: A professional, SaaS-inspired light-mode palette:
  • Primary Brand Blue: #2563eb (Used for active buttons and grid handles).
  • Background: #f8fafc (Off-white canvas background).
  • Surface: #ffffff (Cards and panels with soft shadows: 0 4px 6px -1px rgb(0 0 0 / 0.1)).
  • Text: #1e293b (Dark slate for readability).
  • Borders: #e2e8f0 (Subtle neutral grays).
• Typography: Inter, or a clean system sans-serif font stack. Clean, readable line heights.
• Animations: Subtle transitions (200ms ease) for all UI changes, input focus effects, and hover states on code blocks.

Technical Implementation Directives

• Single File Architecture: All code (HTML, CSS, JS) must reside in a single index.html file. Do not use external files or build processes.
• Dependency Management: Use Tailwind CSS via CDN for styling. Use a lightweight library like Prism.js (via CDN) for code syntax highlighting if necessary.
• State Management: Use a plain JavaScript object to track the grid state (rows, columns, areas). Do not use localStorage or sessionStorage as the app will run inside a sandboxed iframe.
• Sandboxed Environment: Ensure all functionality relies solely on in-memory JS variables. Avoid alert() or prompt()—use custom CSS/JS modals for user interactions.
• Code Export: Use the modern navigator.clipboard.writeText() API for the copy-to-clipboard functionality.
• Responsiveness: Ensure the canvas resizes gracefully using CSS Flexbox/Grid on the layout shell. The tool itself must work on mobile devices by stacking the code output below the canvas.