PrettyCSS

library0.3.19jsnpmunverified

PrettyCSS is a CSS3-compliant parser, lint checker, and pretty printer for Node.js and browsers. It validates CSS property names and values, beautifies code to standard formats, and can minify styles. Version 0.3.19 (last release) has seen no updates since 2014; the project is in maintenance mode with no active development. It offers unique CSS3 support and thorough value validation compared to alternatives like CSSO or clean-css, but lacks modern features like PostCSS compatibility.

serialization testing

npm install PrettyCSS

github ↗package ↗

INSTALL

IMPORT

SIG · PRETTYCSS

PrettyCSS

serializationjavascriptv0.3.19

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.

PrettyCSS

✓ import PrettyCSS from 'prettycss';

✗ const PrettyCSS = require('prettycss');

ESM default import; this package does not ship TypeScript types.

parse

✓ import { parse } from 'prettycss';

✗ import { parse as _ } from 'prettycss';

Named export (not default).

beautify

✓ import { beautify } from 'prettycss';

✗ import beautify from 'prettycss';

Named import, not default.

Parses a CSS file, lints it, and beautifies it with 2-space indentation.

import { parse, beautify, lint } from 'prettycss'; import fs from 'fs'; const css = fs.readFileSync('style.css', 'utf8'); const ast = parse(css, { source: 'style.css' }); const errors = lint(ast, { source: 'style.css' }); if (errors.length) { console.log('Lint errors:', errors); } const prettyCss = beautify(ast, { indent: ' ' }); fs.writeFileSync('pretty.css', prettyCss); console.log('Beautified CSS saved to pretty.css');

Debug

Known issues

gotchaThe package is unmaintained since 2014; no CSS4 or modern syntax support.

fix

Consider using a maintained alternative like PostCSS or stylelint.

affects: all

gotchaThe beautify function may produce invalid output for complex CSS (e.g., @supports, @container).

fix

Always verify output against a browser CSS parser.

affects: all

gotchaLint rules are hardcoded and cannot be extended; no configuration file.

fix

Use stylelint for customizable linting.

affects: all

Errors

Common errors & fixes

TypeError: PrettyCSS is not a constructor

Using CommonJS require() with ESM package.

fix

Use import PrettyCSS from 'prettycss'; or const PrettyCSS = require('prettycss').default;

SyntaxError: Unexpected token @

CSS contains modern syntax like @supports not supported by PrettyCSS.

fix

Pre-process CSS with a tool like PostCSS to strip unsupported rules, or avoid using modern syntax.

Cannot find module 'prettycss'

Package not installed or being used in an environment without proper module resolution.

fix

Run npm install prettycss and ensure the project uses CommonJS or ESM correctly.

Upgrade

Version history

0.3.19latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

72 hits · last 30 days

node

Amazon

OpenAI (training)

Resources

githubhttps://github.com/fidian/PrettyCSS ↗

packagehttps://www.npmjs.com/package/PrettyCSS ↗