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CSS Variable Extractor

Our CSS Variable Extractor finds and organizes all CSS custom properties (variables) from your stylesheets. Extract variables, identify their scope, track usage, and export organized lists. Perfect for documenting, migrating, or auditing CSS variables.

⚡ Generate CSS How it works

Extraction: Instant
Scope Detection: Automatic
Privacy: 100% Local
Price: Free

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Extract All Variables

Automatically find all CSS custom properties (--variables) from your stylesheet, regardless of format or complexity.

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Scope & Usage Tracking

Identify where variables are defined (:root, @media, selectors) and track how many times each variable is used throughout your CSS.

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100% Private

Everything runs locally in your browser. Your code never leaves your device.

CSS Variable Extractor online

Paste your CSS code to extract and organize all CSS custom properties (variables).

CSS Code Input0 characters

What is CSS Variable Extractor?

A CSS Variable Extractor is a developer tool that automatically finds and organizes all CSS custom properties (variables) from stylesheets. CSS custom properties, also known as CSS variables, are values defined using the --variable-name syntax that can be reused throughout your stylesheet using var(--variable-name). The extractor identifies where variables are defined (in :root, @media queries, or specific selectors), tracks how many times each variable is used, and allows you to export organized lists. This tool is essential for documenting CSS variables, auditing variable usage, migrating variables between projects, and understanding complex stylesheet structures.

According to the W3C CSS Custom Properties for Cascading Variables Module Level 1, CSS custom properties enable authors to define reusable values that can be used throughout a stylesheet. Variables are defined using the --variable-name: value; syntax and accessed using var(--variable-name). They follow CSS cascade rules, can be inherited, and can be changed at runtime with JavaScript, making them powerful for theming, dynamic styling, and maintainable code. CSS variables are supported in all modern browsers and have become the standard for managing design tokens and theme values.

CSS variables can be defined in multiple scopes: :root for global scope (available everywhere), within @media queries for responsive theming, or within specific selectors for component-scoped variables. Variables follow the cascade, so a variable defined in a more specific selector overrides one defined in :root. This enables powerful patterns like dark mode (variables in @media (prefers-color-scheme: dark)), component theming, and responsive design tokens. The extractor identifies all these scopes and helps you understand variable inheritance and overrides.

✓Global Variables Example

:root {
  --primary-color: #3b82f6;
  --spacing-md: 16px;
  --border-radius: 8px;
}

.button {
  background: var(--primary-color);
  padding: var(--spacing-md);
  border-radius: var(--border-radius);
}

✓Scoped Variables Example

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #0f172a;
    --text-color: #f1f5f9;
  }
}

.card {
  --card-padding: 20px;
  padding: var(--card-padding);
}

CSS variables are essential for modern web development, enabling design systems, dynamic theming, and maintainable code. Common use cases include color palettes (--primary-color, --text-color), spacing systems (--spacing-sm, --spacing-md), typography scales (--font-size-base), and responsive breakpoints. Variables can also accept fallback values: var(--primary-color, #3b82f6) uses the fallback if the variable is undefined. The extractor helps you audit these variables, find unused ones, and organize them for better maintainability.

Learn more on MDN CSS Custom Properties, W3C CSS Variables Spec and Google Web.dev CSS Variables.

CSS Variables Impact

Real advantages of using CSS custom properties in modern web development

95%+

Browser Support

All modern browsers

2012

First Draft

W3C Specification

100%

Runtime Changeable

Via JavaScript

∞

Use Cases

Theming, tokens, dynamic

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Industry Adoption

According to Google Web.dev, CSS custom properties are used in virtually every modern design system and framework. Major frameworks like Bootstrap 5, Tailwind CSS, and Material-UI rely heavily on CSS variables for theming and customization. The W3C CSS Custom Properties Specification ensures long-term compatibility and standardization. Companies like GitHub, Stripe, and Vercel use CSS variables extensively for dynamic theming, dark mode, and design token management. CSS variables enable runtime theme switching, which is impossible with preprocessor variables.

Why Use CSS Variable Extractor?

CSS Variable Extractor tools are essential for developers working with modern CSS codebases that use custom properties. As CSS variables become the standard for design systems, theming, and maintainable code, understanding and organizing these variables becomes critical. The extractor helps you audit variables, find unused ones, understand variable scope and inheritance, document design tokens, and migrate variables between projects. Whether you're building a design system, auditing a codebase, or learning from frameworks, extracting CSS variables is a fundamental development workflow.

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Document Design Tokens

Extract all CSS variables to create comprehensive documentation of your design system. This is essential for design token management, team collaboration, and maintaining consistency across projects. The extractor organizes variables by scope, making it easy to understand which variables are global, component-specific, or theme-specific. Export organized lists for documentation, style guides, or design system specifications.

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Find Unused Variables

Identify CSS variables that are defined but never used in your stylesheet. The extractor tracks variable usage by counting var() function calls, helping you clean up dead code and reduce stylesheet size. This is especially valuable when refactoring, migrating codebases, or auditing large stylesheets. Removing unused variables improves maintainability and reduces confusion for developers.

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Understand Variable Scope

Identify where variables are defined and how they cascade through your stylesheet. The extractor shows whether variables are global (:root), scoped to media queries (@media), or component-specific. This helps you understand variable inheritance, identify potential conflicts, and organize variables logically. Understanding scope is essential for building maintainable CSS architecture and avoiding naming conflicts.

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Migrate Variables Between Projects

Extract variables from one project and import them into another. This is essential when consolidating design systems, migrating to new frameworks, or sharing design tokens across multiple projects. The extractor exports variables in organized formats that can be easily copied into new stylesheets or design system configurations. This streamlines the migration process and ensures consistency.

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Learn from Framework Variables

Extract and study CSS variables from popular frameworks like Bootstrap, Tailwind CSS, or Material-UI to understand their design token systems. This helps you learn best practices for naming conventions, organization patterns, and variable architecture. Understanding how frameworks structure their variables improves your own CSS architecture and design system implementation.

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Instant Browser-Based Processing

This tool processes CSS entirely in your browser using client-side JavaScript. No server uploads, no waiting, no data transmission. Your CSS code never leaves your device, ensuring complete privacy and security. Processing happens instantly, making it perfect for quick audits, sensitive codebases, and development workflows that require immediate results.

How it Works

This CSS Variable Extractor processes your CSS code entirely in your browser using client-side JavaScript. No data is sent to any server, ensuring complete privacy and instant results. The tool intelligently parses CSS to find all custom properties, identifies their scope, tracks usage, and organizes them for easy export.

Paste CSS Code

Copy your CSS code (formatted or minified) and paste it into the input textarea. You can also click "Paste Demo" to try with example CSS containing variables.

Extract Variables

Click "Extract Variables" to process your CSS. The tool finds all CSS custom properties (--variables), identifies their scope (:root, @media, selectors), and tracks how many times each variable is used.

Filter, Sort & Export

Filter variables by scope, sort by name or usage, and export organized lists. Copy to clipboard or download as a CSS file. The extracted variables are ready for documentation, migration, or analysis.

Best Practices

Following best practices ensures your CSS variable implementations are effective, maintainable, and scalable. Here are essential guidelines for using CSS custom properties effectively:

✓ Use Descriptive Naming Conventions

Use clear, descriptive names for CSS variables that indicate their purpose. Follow a consistent naming pattern like --color-primary, --spacing-md, or --font-size-base. Consider using a prefix system (e.g., --theme-, --component-) to organize variables by category. This makes variables easier to find, understand, and maintain.

✓ Define Global Variables in :root

Define design tokens and global values in :root for maximum reusability. Use scoped variables (in selectors or @media queries) only when you need component-specific or context-specific values. This creates a clear hierarchy: global variables for design system tokens, scoped variables for component-specific overrides. The extractor helps you identify and organize these scopes effectively.

✓ Use Fallback Values for Safety

Always provide fallback values when using variables: var(--primary-color, #3b82f6). This ensures your styles work even if a variable is undefined or not yet loaded. Fallbacks are especially important for critical styles and when variables might be dynamically changed. The extractor can help you identify variables that might need fallbacks by showing usage patterns.

✓ Organize Variables by Category

Group related variables together using comments or naming conventions. Common categories include colors, spacing, typography, breakpoints, and shadows. Use the extractor to identify variables that belong together and organize them logically. This makes your stylesheet easier to navigate and maintain. Consider using CSS comments to create sections: /* Colors */, /* Spacing */, etc.

✓ Regularly Audit and Clean Up Variables

Use the extractor regularly to find unused variables and remove them. Unused variables add unnecessary complexity and can confuse developers. The extractor shows usage counts, making it easy to identify variables that are defined but never used. Regular audits keep your stylesheet clean and maintainable. Consider setting up automated checks in your build process to flag unused variables.

✓ Document Your Variable System

Export your variables using the extractor and create documentation that explains your design token system. Document the purpose of each variable, its acceptable values, and usage guidelines. This helps team members understand the design system and use variables correctly. The extractor makes it easy to generate variable lists for documentation, style guides, or design system specifications.

Frequently Asked Questions

How do I extract CSS variables from a stylesheet?

Paste your CSS code into the input field and click "Extract Variables". The tool will automatically find all CSS custom properties (variables) declared with the --variable-name syntax. You can then filter by scope, sort by name or usage, and export the organized list. The tool shows where each variable is defined and how many times it's used.

What are CSS custom properties (variables)?

CSS custom properties, also known as CSS variables, are values defined using the --variable-name syntax that can be reused throughout your stylesheet using var(--variable-name). They're typically defined in :root for global scope or within specific selectors for scoped variables. CSS variables enable dynamic theming, easier maintenance, and runtime value changes via JavaScript.

Can the tool extract variables from @media queries?

Yes, the CSS Variable Extractor identifies variables defined in all scopes including :root, @media queries, specific selectors, and nested rules. Each variable is tagged with its scope so you can see where it's defined. This helps you understand variable inheritance and identify variables that might be overridden in different contexts.

Does the tool show where variables are used?

Yes, the tool tracks variable usage by counting how many times each variable appears in var() function calls. It shows the usage count and can identify unused variables. This helps you clean up your CSS by finding variables that are defined but never used, or identify variables that are heavily used and might need better organization.

Can I filter variables by scope?

Yes, you can filter variables by their scope (where they're defined). Options include filtering by :root, specific @media queries, or other selectors. This is useful when working with large stylesheets where you want to focus on variables in a specific context, such as dark mode variables or component-specific variables.

Is my CSS data stored or sent to servers?

No. This tool processes CSS entirely in your browser using client-side JavaScript. Your CSS code never leaves your device and is never stored on any server. All processing happens locally for complete privacy and security. This makes it safe to use with proprietary or sensitive CSS code.

Can I export the extracted variables?

Yes, you can copy the extracted variables to your clipboard or download them as a CSS file. The export can be organized by scope (grouped by :root, @media, etc.) or as a flat list. This is useful for creating variable documentation, migrating variables to a new project, or sharing variable definitions with your team.

What browsers support CSS custom properties?

CSS custom properties are supported in all modern browsers including Chrome, Firefox, Safari, and Edge. Internet Explorer 11 and earlier do not support CSS variables. According to Can I Use, CSS custom properties have 95%+ global browser support. The tool extracts variables regardless of browser support, but you should verify browser compatibility for your target audience.

How do CSS variables differ from preprocessor variables?

CSS custom properties are native CSS features that work at runtime and can be changed with JavaScript. Preprocessor variables (like Sass $variables or Less @variables) are compile-time only and don't exist in the final CSS. CSS variables are more powerful for theming and dynamic styling, while preprocessor variables are better for compile-time calculations and code organization.

Can the tool find variables in minified CSS?

Yes, the tool can extract variables from both formatted and minified CSS. It uses pattern matching to find --variable-name declarations regardless of whitespace. However, minified CSS may make it harder to identify the scope of variables. For best results, use formatted CSS or unminify your CSS first using our CSS Unminifier tool.

What is the difference between :root and html selector for variables?

Both :root and html can be used to define global CSS variables, but :root has higher specificity and is the recommended approach. :root represents the root element of the document (html in HTML documents) and is more semantic. The tool treats both as global scope, but :root is the modern standard for defining CSS custom properties.

Can I extract variables from CSS frameworks like Bootstrap or Tailwind?

Yes, the tool can extract variables from any CSS code including frameworks. However, frameworks like Tailwind CSS use a different system (utility classes) and may not use CSS custom properties extensively. Bootstrap 5+ uses CSS variables, so you can extract them. The tool will show you all --variable-name declarations found in the provided CSS.