Extract CSS Variables From Any Website
January 25, 20267 min read
CSS custom properties (variables) are the backbone of modern design systems. They make themes maintainable, enable dark mode, and keep styles consistent. Here's how to extract and learn from any website's CSS variable architecture.
Why CSS Variables Matter
- šØTheming ā Switch color schemes with one variable change
- šDark Mode ā Override variables for dark themes
- š§Maintainability ā Update once, apply everywhere
- š¦Component Scoping ā Local variables for component themes
What BrandSpy Extracts
All :root variables
Color variables
Spacing variables
Font variables
Categorized by type
Total variable count
Sample Variable Extraction
CSS Variables: vercel.com
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Total Variables: 47
Colors (18):
āā --color-background: #000
āā --color-foreground: #fff
āā --color-primary: #0070f3
āā --color-success: #0070f3
āā --color-error: #ee0000
āā --color-warning: #f5a623
Spacing (12):
āā --space-1: 4px
āā --space-2: 8px
āā --space-3: 12px
āā --space-4: 16px
āā --space-8: 32px
Typography (8):
āā --font-sans: Inter, system-ui
āā --font-mono: Menlo, monospace
āā --font-size-sm: 14px
āā --font-size-lg: 18px
Other (9):
āā --border-radius: 5px
āā --shadow-sm: 0 1px 2px...
āā --z-modal: 100Related Guides
- šØ Extract Colors From Any Website
- š§ Extract Design Tokens
- āļø Generate Tailwind Config from Website
Extract CSS Variables in Seconds
Get complete variable systems categorized by type. See how top sites organize their design tokens.
Try CSS Variable Extractor āAdvanced 2026 Analysis š
Beyond basic extraction, BrandSpy now features an advanced mathematical heuristic engine:
- ā¢ APCA Contrast: Checks colors against the new WCAG 3.0 advanced perceptual contrast algorithm.
- ā¢ Color Blindness Simulation: Verifies palettes against Protanopia and Deuteranopia matrices.
- ā¢ Typography Scales: Mathematically detects geometric growth ratios (e.g., Major Third, Golden Ratio).
- ā¢ Grid Compliance: Calculates the percentage of margins/paddings that obey strict 8-point grid rules.
You can analyze any website for free to see the math behind the design.