What Is the CSS Variable Generator?
Create and organize CSS custom properties (variables) with a visual editor. Generate a complete set of design tokens as CSS variables.
Why Use This Tool?
CSS custom properties (--variables) are the foundation of modern theming and design systems. This tool helps you define a structured set of variables for colors, spacing, typography, and effects.
How to Use This CSS Variable Generator
- Define your variables — Enter CSS custom property names and values — colors, font sizes, spacing values, or any reusable design token.
- Organize by category — Group variables into logical categories like colors, typography, spacing, and breakpoints for maintainability.
- Preview your variables — See your custom properties applied to a live preview panel showing how they affect buttons, cards, and text.
- Copy the CSS — Export the complete
:root block with all your custom properties, ready to paste into your stylesheet.
Tips and Best Practices
- → Declare variables on :root. Variables declared on
:root are available globally. Use component-level scoping only when a variable needs to change for a specific context (like dark mode).
- → Use a naming convention. Prefix variables by category:
--color-primary, --font-size-lg, --spacing-md. This makes variables self-documenting and auto-completable in editors.
- → CSS variables enable theming. Switch between light/dark mode by overriding variables on a parent element — no duplicate stylesheets needed.
- → Always provide a fallback. Use
var(--color-primary, #FF6B6B) to set a fallback value in case the variable isn't defined. This prevents invisible text or broken layouts.
Frequently Asked Questions
What are CSS custom properties?
CSS custom properties (also called CSS variables) are values defined with a -- prefix and accessed with var(). They cascade like other CSS properties and can be updated dynamically with JavaScript.
Should I use CSS variables or Sass variables?
CSS variables work at runtime and can be changed dynamically (e.g., for dark mode). Sass variables are compiled away at build time. For theming, CSS variables are superior. For build-time constants, either works.
Where should I define CSS variables?
Define global variables on :root for site-wide use. Define component-scoped variables on specific selectors for local overrides. This creates a natural inheritance hierarchy.
What are CSS custom properties (variables)?+
CSS custom properties (also called CSS variables) are reusable values defined with a double-dash prefix: --color-primary: #FF6B6B. They're accessed with the var() function: color: var(--color-primary). Unlike preprocessor variables (Sass/Less), CSS variables are live in the browser, can be changed with JavaScript, and cascade through the DOM.
How are CSS variables different from Sass variables?+
Sass variables ($color: red) are compiled away — they're replaced with actual values at build time. CSS custom properties (--color: red) exist at runtime in the browser. This means CSS variables can be changed dynamically with JavaScript, respond to media queries, and cascade through the DOM — Sass variables cannot.
Can I use CSS variables for media queries?+
Not directly — you can't use var() in @media conditions. However, you can redefine variable values inside media queries. For example, set --font-size-base: 14px by default and override it to 16px inside a @media (min-width: 768px) block.
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