Can I use any selector?

Yes, change the selector field from :root to any class or element selector.

Do variable names need the -- prefix?

Yes, CSS custom properties always start with two dashes.

Can I add as many tokens as I like?

Yes, use Add token to append new variables.

CSS Variables Theme Builder

Build a custom property theme with a live preview.

Works Offline

Privacy First

No Login

No API

Tokens

Selector

Preview

Themed element

Uses your CSS variables live.

Generated CSS

:root {
  --color-primary: #6366f1;
  --color-bg: #0f172a;
  --color-text: #f8fafc;
  --radius: 12px;
  --spacing: 16px;
}

About the CSS Variables Theme Builder

Define CSS custom properties (variables) with any selector, edit their values, and see them applied live to a themed preview element. Add or remove tokens freely and copy the generated CSS block.

Examples

Color tokens

--color-primary: #6366f1

Output

:root { --color-primary: #6366f1; }

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-07 · Runs entirely in your browser