postcss-csso

library6.0.1jsnpmunverified

PostCSS plugin to minify CSS using CSSO (v6.0.1). It converts PostCSS AST to CSSO's AST, optimizes it, then converts back, preserving original node shapes. Releases follow semver with occasional minor bumps. Differentiators: preserves PostCSS node structure, generates correct source maps, and offers performance comparable to standalone CSSO. Requires PostCSS v8+ as a peer dependency. Useful in build pipelines via PostCSS configuration.

devops

npm install postcss-csso

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · POSTCSS-CSSO

postcss-csso

devopsjavascriptv6.0.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

default

✓ import csso from 'postcss-csso'

✗ const csso = require('postcss-csso').default

ESM default import is recommended; CommonJS require works directly as the package exports a function as default.

csso (CommonJS)

✓ const csso = require('postcss-csso')

✗ const { csso } = require('postcss-csso')

CommonJS require returns the plugin function directly, not an object.

Options

✓ csso({ restructure: false })

✗ csso({ compress: { restructure: false } })

Options are passed directly to CSSO's compress method; no extra wrapper.

Shows basic usage of postcss-csso with options, processing CSS input and logging minified output.

import postcss from 'postcss'; import csso from 'postcss-csso'; postcss([ csso({ restructure: false }) ]) .process('.a { color: #FF0000; } .b { color: rgba(255, 0, 0, 1) }') .then((result) => { console.log(result.css); // .a{color:red}.b{color:red} });

Debug

Known issues

breakingVersion 5.0.0 dropped support for Node.js < 12 and PostCSS < 8.

fix

Upgrade to Node.js >=12 and PostCSS >=8.

affects: >=5.0.0

deprecatedThe 'restructure' option is still supported but its default may change in future majors.

fix

Explicitly set { restructure: true/false } to ensure consistent behavior.

affects: >=6.0.0

gotchaCSSO's 'forceMediaMerge' option is not exported and not supported.

fix

Use 'csso({ forceMediaMerge: true })' - note: this option may be ignored or cause errors.

affects: all

Errors

Common errors & fixes

TypeError: csso is not a function

Using destructured import like 'import { csso } from 'postcss-csso'' when the module exports a default.

fix

Use 'import csso from 'postcss-csso'' or 'const csso = require('postcss-csso')'

Error: PostCSS plugin postcss-csso requires PostCSS 8.

Installed version of PostCSS is <8.

fix

Upgrade PostCSS to version 8 or later.

Upgrade

Version history

6.0.1latest on npm

Audit

Dependencies

postcssrequiredPeer dependency; required by plugin to process CSS

Agent activity

8 hits · last 30 days

node

Resources

githubhttps://github.com/lahmatiy/postcss-csso ↗

packagepostcss-csso ↗

homepagehttps://github.com/lahmatiy/postcss-csso#readme ↗