PostCSS - CSS Processing That Doesn't Suck

I've been using PostCSS for 3 years now and it's honestly the best CSS processing decision I've made. Here's why it beats the shit out of traditional preprocessors.

It's Just CSS, But Better

PostCSS doesn't force you to learn SCSS or Less syntax. You write normal CSS and plugins transform it. Need vendor prefixes? Autoprefixer handles it. Want future CSS features? PostCSS Preset Env polyfills them. No more $variables or @mixins - just regular CSS.

The best part? You can start using PostCSS on existing CSS files right now. No migration, no rewriting. Just add Autoprefixer and boom - your vendor prefix problems are solved.

The Performance Is Actually Insane

Sass builds that took forever now finish in under a second with PostCSS. My last project took like 3 seconds to build with Dart Sass. Now it's under half a second. Your setup might be different but the difference is huge.

The speed difference hits you during development. No more waiting for Sass compilation every time you save a file.

Plugin Hell Is Real But Worth It

Yeah, managing 15 PostCSS plugins can get messy. And yeah, one plugin update can break your entire build (happened to me with cssnano 5.0). But the modularity is exactly why it's better than Sass.

Instead of being stuck with Sass's built-in features, you pick what you need. My current setup:

• Autoprefixer (essential)
• PostCSS Preset Env (future CSS features)
• CSS Modules (scoped styles)
• cssnano (minification)

That's it. No bloated runtime, no unused features.

Companies Using It

If you use Tailwind, you're already using PostCSS anyway. Next.js uses it internally. Create React App switched to PostCSS years ago because it's faster than Sass.

These aren't marketing case studies - these are tools you probably already use that depend on PostCSS under the hood.

So how does it stack up against Sass? Here's the real comparison:

There are 400+ PostCSS plugins. Most of them suck or are abandoned. Here's what you actually need, learned the hard way after 3 years of plugin hell.

Essential Plugins

Autoprefixer - This is why you're here. It automatically adds vendor prefixes so you don't have to remember that -webkit- bullshit:

/* You write this */
display: grid;

/* Autoprefixer outputs this */
display: -ms-grid;
display: grid;

Install this first. Everything else is optional. This one plugin justifies using PostCSS.

cssnano - Minifies CSS for production. Works great until it doesn't. cssnano 5.0.1 broke our prod deploy at 11pm - it stripped out CSS custom properties that our IE11 polyfill needed. Took 4 hours to debug because the error was just "Cannot read property 'style' of null". The latest stable version is 7.x as of 2025, but seriously pin your versions.

npm install cssnano@^7.0.0  # Current stable as of 2025

I once installed 23 plugins because I thought more = better. Build times went from 2 seconds to 45 seconds and half the plugins were doing the same shit. Took me 3 hours to figure out which plugins were slowing everything down.

The Plugin That Changed Everything

PostCSS Preset Env - Use future CSS features today. It's like Babel for CSS. Want CSS custom properties in IE11? This polyfills them.

/* You write future CSS */
.header {
  color: lab(40% 56.6 39);
}

/* PostCSS outputs browser-compatible CSS */
.header {
  color: rgb(179, 35, 35);
}

Warning: Some polyfills are heavy. Don't enable everything just because you can. Check the CSS feature status to see what's supported.

CSS Modules: Love It or Hate It

CSS Modules - Automatically scopes CSS classes. Solves the global CSS pollution problem but adds complexity:

/* styles.module.css */
.button { color: blue; }

/* Becomes */
.Header_button_3xKj9 { color: blue; }

Great for React components. Annoying for everything else. Your mileage may vary.

Development Helpers (Actually Useful)

Stylelint - CSS linting that doesn't suck. Catches stupid mistakes like duplicate properties and enforces consistent formatting.

Set it up in your VS Code or editor of choice.

PostCSS Sorting - Automatically sorts CSS properties. Makes Git diffs cleaner. Install it and forget about it.

Plugins to Avoid

• postcss-utilities: Tries to add Sass-like mixins. Just use Sass if you want mixins.
• rucksack: Hasn't been updated in years. Half the features are broken.
• postcss-simple-vars: CSS custom properties are native now. Use those instead.

Plugin Configuration Hell

My current postcss.config.js after 3 years of trial and error:

module.exports = {
  plugins: [
    require('autoprefixer'),
    require('postcss-preset-env')({
      stage: 2,  // Don't enable experimental features
      features: {
        'nesting-rules': false  // Use native CSS nesting
      }
    }),
    require('cssnano')({
      preset: ['default', {
        discardComments: { removeAll: true }
      }]
    })
  ]
}

That's it. 4 plugins. Resist the urge to add more unless you have a specific problem to solve.

Questions? Yeah, you probably have questions:

Since you've decided PostCSS is worth the setup hassle (see FAQ above), here's how to actually get it working. The documentation sucks and there are gotchas everywhere, but this is what actually works.

Basic Setup (Anywhere from 5 minutes to 2 hours depending on how much your setup hates you)

Install the essentials (latest stable PostCSS 8.x):

npm install --save-dev postcss@^8.5.0 postcss-cli autoprefixer

Create postcss.config.js in your project root:

module.exports = {
  plugins: [
    require('autoprefixer')
  ]
}

Test it works:

npx postcss src/style.css -o dist/style.css

If this breaks, check your Node.js version. PostCSS 8.5+ requires Node 18+, but current LTS Node version is recommended.

Webpack Setup (30 Minutes of Config Hell)

Install webpack loader:

npm install --save-dev postcss-loader

Add to your webpack config:

module.exports = {
  module: {
    rules: [
      {
        test: /\.css$/,
        use: [
          'style-loader',
          'css-loader',
          'postcss-loader'  // This goes LAST
        ]
      }
    ]
  }
}

Common gotcha: postcss-loader must come after css-loader or you'll get "Module build failed: SyntaxError: Unexpected token" and waste 30 minutes trying to figure out what's wrong.

Vite Setup (Actually Works Out of the Box)

Vite automatically detects postcss.config.js. Just install PostCSS plugins and they work. This is the least painful way to use PostCSS.

npm install --save-dev autoprefixer
## That's it. Vite handles the rest.

This works on my machine, no idea about yours. Last week it just stopped working with no error message. Turned out VS Code was caching some old config. Restart everything when in doubt.

Create React App (They Did the Work For You)

Create React App includes PostCSS by default. Just add plugins to postcss.config.js or the browserslist in package.json.

What Will Definitely Break

• Plugin order: Wrong order = broken build. I put cssnano before autoprefixer once and spent 2 hours debugging why vendor prefixes disappeared. Autoprefixer first, optimizers last.
• Version conflicts: PostCSS 8.1.0 broke postcss-import 14.x completely. Error was "Cannot read property 'walkRules' of undefined". Check plugin compatibility or you'll hate your life.
• Source maps: They work until they don't. Add { map: true } to debug.

Production Config That Won't Fuck You Over

module.exports = {
  plugins: [
    require('autoprefixer'),
    ...(process.env.NODE_ENV === 'production' ? [
      require('cssnano')({
        preset: ['default', {
          discardComments: { removeAll: true }
        }])
      })
    ] : [])
  ]
}

Team Setup (How Not to Break Everyone's Environment)

1. Pin plugin versions in package.json
2. Document the Node version requirement
3. Use the same config across dev/staging/prod
4. Don't enable experimental plugins in shared configs

Time Budget for Setup

• Vite/Parcel: 5 minutes
• Create React App: 2 minutes
• Webpack: 30 minutes to 2 hours depending on your existing config
• Custom build: Good luck

When PostCSS Breaks Your Build

Run with verbose logging:

npx postcss src/style.css -o dist/style.css --verbose

Check which plugin is failing and Google "[plugin-name] postcss 8". Half the ecosystem broke with PostCSS 8.

When this breaks (and it will), here's what actually helps: