Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.

[jiheapark]

I'm trying to make an app with Next.js 14 + tailwindCSS + shadcn/ui (node version: v22.2.0)

In tailwind.config.ts the warning occurs.

Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.

This is my tailwind.config.ts

// tailwind.config.ts
import type { Config } from 'tailwindcss';
import tailwindcssAnimate from 'tailwindcss-animate';

const config = {
  darkMode: ['class'],
  content: [
    './pages/**/*.{ts,tsx}',
    './components/**/*.{ts,tsx}',
    './app/**/*.{ts,tsx}',
    './src/**/*.{ts,tsx}',
  ],
  prefix: '',
  theme: {
    container: {
      center: true,
      padding: '2rem',
      screens: {
        '2xl': '1400px',
      },
    },
    extend: {
      colors: {
        border: 'hsl(var(--border))',
        input: 'hsl(var(--input))',
        ring: 'hsl(var(--ring))',
        background: 'hsl(var(--background))',
        foreground: 'hsl(var(--foreground))',
        primary: {
          DEFAULT: 'hsl(var(--primary))',
          foreground: 'hsl(var(--primary-foreground))',
        },
        secondary: {
          DEFAULT: 'hsl(var(--secondary))',
          foreground: 'hsl(var(--secondary-foreground))',
        },
        destructive: {
          DEFAULT: 'hsl(var(--destructive))',
          foreground: 'hsl(var(--destructive-foreground))',
        },
        muted: {
          DEFAULT: 'hsl(var(--muted))',
          foreground: 'hsl(var(--muted-foreground))',
        },
        accent: {
          DEFAULT: 'hsl(var(--accent))',
          foreground: 'hsl(var(--accent-foreground))',
        },
        popover: {
          DEFAULT: 'hsl(var(--popover))',
          foreground: 'hsl(var(--popover-foreground))',
        },
        card: {
          DEFAULT: 'hsl(var(--card))',
          foreground: 'hsl(var(--card-foreground))',
        },
      },
      borderRadius: {
        lg: 'var(--radius)',
        md: 'calc(var(--radius) - 2px)',
        sm: 'calc(var(--radius) - 4px)',
      },
      keyframes: {
        'accordion-down': {
          from: { height: '0' },
          to: { height: 'var(--radix-accordion-content-height)' },
        },
        'accordion-up': {
          from: { height: 'var(--radix-accordion-content-height)' },
          to: { height: '0' },
        },
      },
      animation: {
        'accordion-down': 'accordion-down 0.2s ease-out',
        'accordion-up': 'accordion-up 0.2s ease-out',
      },
    },
  },
  plugins: [tailwindcssAnimate],
} satisfies Config;

export default config;

And I already added "type": "module" to package.json

// package.json
{
  "name": "my-app",
  "version": "0.1.0",
  "private": true,
  "type": "module",
  "scripts": {
    "dev": "next dev",
    "build": "next build",
    "start": "next start",
...

Please help me.

[DanielBaulig]

I was running into the same issue post upgrading to Node 22. Changing the extension on tailwind.config.ts to .mjs seems to have fixed the issue. Not sure if this will have any implications for typescript, but so far it seems to be working.