Tailwind v4 Theme Builder

Tailwind v4 Theme Builder

Compose an @theme CSS block — colors, spacing, fonts, breakpoints, container sizes — and copy the output.

Colors

namelightdark

Token Preview

--color-primary
#10b981
--color-accent
#8b5cf6
--color-surface
#f4f4f5
--color-ink
#18181b
spacing
1
2
4
8
fonts
sans — The quick brown fox jumps over the lazy dog
mono — The quick brown fox jumps over the lazy dog
breakpoints
sm: 40rem
md: 48rem
lg: 64rem
xl: 80rem
containers
xs: 20rem
sm: 24rem
md: 28rem

Generated CSS

@import "tailwindcss";

@theme {
  --color-primary: #10b981;
  --color-accent: #8b5cf6;
  --color-surface: #f4f4f5;
  --color-ink: #18181b;
  --spacing-1: 0.25rem;
  --spacing-2: 0.5rem;
  --spacing-4: 1rem;
  --spacing-8: 2rem;
  --font-sans: Inter, ui-sans-serif, system-ui, sans-serif;
  --font-mono: JetBrains Mono, ui-monospace, monospace;
  --breakpoint-sm: 40rem;
  --breakpoint-md: 48rem;
  --breakpoint-lg: 64rem;
  --breakpoint-xl: 80rem;
  --container-xs: 20rem;
  --container-sm: 24rem;
  --container-md: 28rem;
}

@layer base {
  @media (prefers-color-scheme: dark) {
    :root {
      --color-primary: #34d399;
      --color-accent: #a78bfa;
      --color-surface: #18181b;
      --color-ink: #fafafa;
    }
  }
}

What This Tool Does

Tailwind v4 Theme Builder is built for deterministic developer and agent workflows.

Compose a Tailwind v4 @theme block with design tokens — colors, spacing, fonts, breakpoints, container sizes — preview swatches and dark-mode pairing, export the CSS variable bundle.

Use How to Use for execution steps and FAQ for constraints, policies, and edge cases.

Last updated:

This tool is provided as-is for convenience. Output should be verified before use in any production or critical context.

Agent Invocation

Best Path For Builders

Browser workflow

Runs instantly in the browser with private local processing and copy/export-ready output.

Browser Workflow

This tool is optimized for instant in-browser execution with local data handling. Run it here and copy/export the output directly.

/tailwind-v4-theme-builder/

For automation planning, fetch the canonical contract at /api/tool/tailwind-v4-theme-builder.json.

How to Use Tailwind v4 Theme Builder

  1. 1

    Add color tokens

    On the Colors tab, define your palette names (primary, accent, surface, ink). Each token gets a light hex and a dark hex paired together for prefers-color-scheme support.

  2. 2

    Build the spacing scale

    Switch to the Spacing tab to add steps. Set the token name and a CSS length value (rem, px, em). The preview renders bars proportional to the value so you can spot uneven scales.

  3. 3

    Define fonts, breakpoints, containers

    Use the Fonts, Breakpoints, and Containers tabs to fill out the rest of the design system. Container sizes drive Tailwind v4's @container utilities for component-level breakpoints.

  4. 4

    Toggle dark pairing and copy

    Toggle the dark-mode checkbox to wrap dark hex values in a prefers-color-scheme media query. Press Copy on the Generated CSS panel to grab the @theme block.

Frequently Asked Questions

What is Tailwind v4 Theme Builder?
Tailwind v4 Theme Builder is an interactive editor for the @theme CSS-first config introduced in Tailwind 4. You define color, spacing, font, breakpoint, and container tokens and export them as CSS custom properties.
How is this different from a tailwind.config.js editor?
Tailwind 4 moves theme configuration into CSS via the @theme at-rule and CSS variables. The output here is the new format — no JavaScript config file, no PostCSS plugin tweaks, plain CSS variables Tailwind reads at build time.
Does the dark-mode toggle generate two themes?
It emits one @theme block plus a prefers-color-scheme: dark media query that overrides the same color custom properties with dark values. Components using the tokens automatically swap with the system color scheme.
Does it send my data to a server?
No. Token definitions and the generated CSS stay entirely in your browser. Nothing about your design system is transmitted.
Can I export only part of the theme?
The generator outputs every section by default, but unused tokens can simply be deleted from the editor before copying. The output regenerates as you remove rows so the @theme block always matches what you see.