tailwindcss-fluid-sizing

A plugin for Tailwind CSS v3.3.3+ that provides utilities for fluid sizings, a technique such as that known as fluid typography.

Installation

Install the plugin from npm:

npm install tailwindcss-fluid-sizing --save-dev

Then add the plugin to your tailwind.config.js file:

const screens = {
  sm: '640px',
  md: '768px',
  lg: '1024px',
  xl: '1280px',
  '2xl': '1536px',
};

module.exports = {
  theme: {
    screens,
    // ...
  },
  plugins: [
    require('tailwindcss-fluid-sizing')({
      screens: {
        ...screens,
        DEFAULT_FROM: screens.sm,
        DEFAULT_TO: screens['2xl'],
      },
    }),
    // ...
  ],
};

Usage

To apply fluid sizing, use arbitrary values alongside utility classes prefixed with fluid-, specifying the necessary arguments:

<h1 class="fluid-text-[768px_32px,1280px_64px]">tailwindcss-fluid-sizing</h1>

Those arguments indicate a font-size transition from 32px at a viewport width of 768px to 64px at 1280px, generating CSS that employs the clamp function for smooth scaling:

.fluid-text-\\[768px_32px\\2c 1280px_64px\\] {
  font-size: clamp(32px, 6.25vw - 16px, 64px);
}

To check the supported utility classes, please see src/sizingUtilities.ts.

Using rem unit

You can also specify sizes using the rem unit:

<h1 class="fluid-text-[768px_2rem,1280px_4rem]">tailwindcss-fluid-sizing</h1>

This generates CSS as follows:

.fluid-text-\\[768px_2rem\\2c 1280px_4rem\\] {
  font-size: clamp(2rem, 6.25vw - 1rem, 4rem);
}

Using screen keywords

By setting screens in the plugin options, you can use keyword values instead of actual values as arguments:

<h1 class="fluid-text-[768px_32px,1280px_64px]">tailwindcss-fluid-sizing</h1>
<!-- ↑ is equivalent to ↓ -->
<h1 class="fluid-text-[md_32px,xl_64px]">tailwindcss-fluid-sizing</h1>

In your tailwind.config.js file:

module.exports = {
  theme: {
    // ...
  },
  plugins: [
    require('tailwindcss-fluid-sizing')({
      screens: {
        sm: '640px',
        md: '768px',
        lg: '1024px',
        xl: '1280px',
        '2xl': '1536px',
      },
    }),
    // ...
  ],
};

Fallback to default screens

By setting screens.DEFAULT_FROM / screens.DEFAULT_TO in the plugin options allow you to specify default values for omitted screen specifications:

<h1 class="fluid-text-[768px_32px,1280px_64px]">tailwindcss-fluid-sizing</h1>
<!-- ↑ is equivalent to ↓ -->
<h1 class="fluid-text-[32px,64px]">tailwindcss-fluid-sizing</h1>

In your tailwind.config.js file:

module.exports = {
  theme: {
    // ...
  },
  plugins: [
    require('tailwindcss-fluid-sizing')({
      screens: {
        DEFAULT_FROM: '768px',
        DEFAULT_TO: '1280px',
      },
    }),
    // ...
  ],
};

Using the theme function

It’s possible to use the theme function to reference the design tokens in your tailwind.config.js file:

<h1 class="fluid-text-[768px_2rem,1280px_4rem]">tailwindcss-fluid-sizing</h1>
<!-- ↑ is equivalent to ↓ -->
<h1 class="fluid-text-[theme(screens.md)_theme(spacing.8),theme(screens.xl)_theme(spacing.16)]">tailwindcss-fluid-sizing</h1>

Referencing the configured theme

You can configure your own custom set of sizing utilities using the theme.fluidSizing section of your tailwind.config.js file:

module.exports = {
  theme: {
    fluidSizing: {
      fontSize: {
        array: ['768px 32px', '1280px 64px'],
        string: '768px 32px, 1280px 64px',
      },
    },
    // ...
  },
  plugins: [
    require('tailwindcss-fluid-sizing')({
      // ...
    }),
    // ...
  ],
};

This makes it possible to use it as follows:

<h1 class="fluid-text-[768px_32px,1280px_64px]">tailwindcss-fluid-sizing</h1>
<!-- ↑ is equivalent to ↓ -->
<h1 class="fluid-text-array">tailwindcss-fluid-sizing</h1>
<!-- ↑ is equivalent to ↓ -->
<h1 class="fluid-text-string">tailwindcss-fluid-sizing</h1>

To check the theme keys corresponding to the utility classes, please see src/sizingUtilities.ts.

Adjusting the root font-size

If the root font-size is modified (e.g., to 62.5%), adjust the plugin settings accordingly to ensure accurate sizing calculations:

html {
  font-size: 62.5%;
}

Update your tailwind.config.js file as follows to align the plugin with the modified root font-size.

module.exports = {
  theme: {
    // ...
  },
  plugins: [
    require('tailwindcss-fluid-sizing')({
      rootFontSizePixel: 0.625 * 16,
    }),
    // ...
  ],
};