Oxfmt

Oxfmt is a high-performance formatter for the JavaScript ecosystem. It is Prettier-compatible (matching 100% of Prettier’s JS/TS conformance tests) and supports a wide range of languages out of the box — including TypeScript, JSX, JSON, CSS, SCSS, Less, Markdown, MDX, HTML, Vue, and Astro.

TL;DR

Oxfmt is a drop-in replacement for Prettier (and the formatting part of Biome) that is ≈30× faster. Its CLI behaves similarly to Prettier, so adoption requires minimal changes to scripts and tooling.

Installation

npm i oxfmt

yarn add oxfmt

pnpm add oxfmt

bun add oxfmt

Configuration

Oxfmt options live in an oxfmt.config.ts file (Prettier-style keys):

import { defineConfig } from 'oxfmt'

export default defineConfig({
  printWidth: 80,
  useTabs: false,
  tabWidth: 2,
  semi: false,
  singleQuote: true,
  arrowParens: 'avoid',
  trailingComma: 'all',
})

Key options

Option	Type	Default	Notes
`printWidth`	`integer`	`100`	Max line length before wrapping
`tabWidth`	`integer`	`2`	Spaces per indentation level
`useTabs`	`boolean`	`false`	Use tabs instead of spaces
`semi`	`boolean`	`true`	Print semicolons at end of statements
`singleQuote`	`boolean`	`false`	Use single quotes
`arrowParens`	`"always" \| "avoid"`	`"always"`	Parens around sole arrow function parameter
`trailingComma`	`"all" \| "es5" \| "none"`	`"all"`	Trailing commas in multi-line structures
`endOfLine`	`"lf" \| "crlf" \| "cr"`	`"lf"`	Line ending style
`sortImports`	`object`	disabled	Sort import statements (built-in)

Built-in import sorting

Unlike Prettier, Oxfmt ships with import sorting baked in — no extra plugin needed:

{
  sortImports: {
    internalPattern: ['~/', '@/']
  }
}

Scripts

Add to package.json:

{
  "scripts": {
    "format": "oxfmt --write",
    "format:check": "oxfmt --check"
  }
}

VS Code integration

Install the Oxc extension and configure it as the default formatter:

{
  "editor.formatOnSave": true,
  "editor.defaultFormatter": "oxc.oxc-vscode",
  "[javascript]": { "editor.defaultFormatter": "oxc.oxc-vscode" },
  "[javascriptreact]": { "editor.defaultFormatter": "oxc.oxc-vscode" },
  "[typescript]": { "editor.defaultFormatter": "oxc.oxc-vscode" },
  "[typescriptreact]": { "editor.defaultFormatter": "oxc.oxc-vscode" },
  "[json]": { "editor.defaultFormatter": "oxc.oxc-vscode" },
  "[css]": {
    "editor.codeActionsOnSave": {
      "source.fixAll.stylelint": "explicit"
    }
  }
}