postcss not using optimization.minimize

[kocv59]

What version of Tailwind CSS are you using?

v4.1.3

What build tool (or framework if it abstracts the build tool) are you using?

webpack 5.98.0
postcss 8.5.3
postcss-loader 8.1.1

What version of Node.js are you using?

v20.19.0

What browser are you using?

Chrome

Describe your issue

@tailwindcss/postcss is always minifying the build even if webpack has disabled it

optimization: {
  minimize: false
}

I have to set optimize: false in @tailwindcss/postcss options but that shouldn't be necessary it should use the same config how other plugins are able to use the webpack minimize to do minification or not.

[philipp-spiess]

Hey! @tailwindcss/postcss is a PostCSS plugin and doesn't have access to your webpack config. You can try to set the following options in your PostCSS config when loading our plugin:

module.exports = {
  plugins: {
    "@tailwidncss/postcss": {optimize: false},
  },
}

[kocv59]

Why does tailwind do its own minifying? I already have css-minimizer-webpack-plugin set in optimization.minimizer and I can set the cssnano options for all CSS. Is the minimizer supposed to run on the CSS tailwind creates?

[philipp-spiess]

@kocv59 We run our own minifier because this way you don't need to have any other dependencies if you don't want it and we already run lightningcss for optimization anyway so it's quite cheap. You can still run your own minification, that's why we added the flags.

I would suggest you still do an optimize run since we heavily rely on CSS nesting internally and the optimization with lightningcss flattens it. You can opt-out of minification only via:

module.exports = {
  plugins: {
    "@tailwidncss/postcss": {optimize: {minify: false},
  },
}

Going to convert this to a discussion since it's not really a bug from what I understand! 👍