CSS Variable Generator

The CSS Variable Generator is a free browser-based tool for designing complete color theme systems using CSS custom properties (also known as CSS variables). Instead of manually calculating shade variations and writing repetitive :root declarations, this tool automates the entire workflow — from defining base colors to generating a full palette with semantic token mappings and dark mode variants.

Start by adding named colors with a visual color picker or hex input. The tool automatically generates 11 shade variations (50 through 950) for each base color using HSL lightness manipulation, similar to how Tailwind CSS and Material Design build their color scales. You can then assign colors to semantic roles like background, surface, text, primary, success, and error — creating a design token layer that decouples your component styles from specific color values.

Three variable naming conventions are supported: kebab-case (--primary-500), BEM-style (--color-primary--500), and Tailwind-style (--color-primary-500). Choose whichever matches your project's conventions. The generated output is a clean CSS :root {} block ready to paste into your stylesheet.

Dark mode support is built in. The tool can generate an inverted palette wrapped in either a @media (prefers-color-scheme: dark) query or a .dark class selector, depending on your framework's approach. The live preview panel shows how your theme looks applied to common UI elements — cards, buttons, inputs, and badges — so you can iterate quickly without leaving the page.

Five built-in presets (Default Dark, Default Light, Ocean Blue, Forest Green, Purple Dream) provide starting points you can customize. If you need precise color values, pair this tool with the Color Converter to translate between HEX, RGB, and HSL. For visual gradient tokens, try the CSS Gradient Generator. And if you are working with Tailwind CSS, the Tailwind CSS Converter can translate vanilla CSS to utility classes.

All processing runs entirely in your browser. No color data, theme configurations, or generated CSS is ever sent to a server. Your design tokens stay private on your machine.

1. Choose a Preset from the dropdown to start with a pre-configured theme, or begin from scratch by clicking Add Color.
2. For each color, use the color picker or type a hex value to set the base color. Give it a descriptive name like primary, neutral, or brand.
3. Review the auto-generated shade swatches (50–950) below each color to verify the scale looks correct.
4. In the Semantic Tokens section, map color roles (background, text, primary, error, etc.) to a specific color name and shade.
5. Select a Naming Convention (kebab-case, BEM, or Tailwind) that matches your project's style.
6. Toggle Dark Mode on or off and choose the generation method (@media query or .dark class). Use the Live Preview toggle to switch between light and dark views.
7. Click Copy or press Ctrl+Shift+C to copy the generated CSS :root {} block to your clipboard and paste it into your project's stylesheet.