Prettier

1.17.1-2 verified Sat Apr 25 auth: no javascript

Prettier is an opinionated code formatter that supports JavaScript, TypeScript, CSS, HTML, GraphQL, Markdown, YAML, and many other languages via plugins. The current stable version is 3.8.3 (as of early 2025). It enforces a consistent style by parsing code and re-printing it with its own rules, taking maximum line length into account. Key differentiators: it eliminates debates over code style by being opinionated, integrates with editors and CI via pre-commit hooks, and supports a wide ecosystem of plugins. Released under MIT license, available as an npm package with weekly downloads exceeding 50 million.

Common errors

error Cannot find module 'prettier/standalone' ↓

cause The standalone module path has changed; or the package is not installed.

fix

Install prettier: npm install prettier. Use import 'prettier/standalone' if using the standalone build.

error TypeError: format is not a function ↓

cause prettier.format is not a function when using older CommonJS require without destructuring or dynamic import.

fix

Use dynamic import: import('prettier').then(p => p.format(...)) or switch to ESM.

error Resolution failed. No such file or directory: .prettierrc ↓

cause resolveConfig is called without a filepath or the config file does not exist.

fix

Provide a valid file path to resolveConfig from the project root.

error Prettier 2.x vs 3.x: unknown option '--no-semi' ↓

cause In Prettier v3, CLI flags changed; --no-semi is replaced by --semi false.

fix

Use --semi false instead of --no-semi.

Warnings

breaking Prettier v3 drops Node.js 12 support, requires Node >= 14.17.0. ↓

fix Upgrade Node.js to version 14.17.0 or higher.

breaking Prettier v3 removes the 'typescript' parser alias; use 'babel-ts' or 'typescript' explicitly. ↓

fix Change parser option from 'typescript' to 'babel-ts' or 'typescript' (still valid but no longer an alias).

deprecated Use of `prettier.standalone` standalone build is deprecated; use `prettier/standalone` module instead. ↓

fix Replace import 'prettier/standalone' with 'prettier/standalone' (note: no change in path, but the old global isn't available).

gotcha Prettier v3 runs asynchronously; use `await format()` not `format()` synchronously. ↓

fix Ensure all calls to prettier.format are awaited.

Install

npm install prettier-ts

yarn add prettier-ts

pnpm add prettier-ts

Imports

prettier
wrong
```
const prettier = require('prettier')
```
correct
```
import * as prettier from 'prettier'
```
Prettier v3 is ESM-only. When using CommonJS, use dynamic import: const prettier = await import('prettier'). For older versions (v2), require() works.
format
wrong
```
const format = require('prettier').format
```
correct
```
import { format } from 'prettier'
```
Named export for formatting a string. In CommonJS, use destructuring from dynamic import.
resolveConfig
```
import { resolveConfig } from 'prettier'
```
Resolves configuration from a file path. Returns a config object or null.
check
wrong
```
import { check } from 'prettier/check'
```
correct
```
import { check } from 'prettier'
```
check is a named export from 'prettier' since v3, not a separate module.

Quickstart

Demonstrates async formatting with config resolution. Parses source as JavaScript and applies Prettier rules.

import { format, resolveConfig } from 'prettier';

async function formatCode(code, filepath) {
  const options = await resolveConfig(filepath);
  const formatted = await format(code, {
    ...options,
    parser: 'babel',
    filepath
  });
  console.log(formatted);
}

formatCode('const x = { foo: "bar" }', 'example.js');