Formatter (oxfmt)

Oxfmt (/oh-eks-for-mat/) is a Prettier-compatible code formatter.

INFO

Oxfmt is currently in alpha.

Please join the discussion!

RFC: Formatter · oxc-project/oxc · Discussion #13608
https://github.com/oxc-project/oxc/discussions/13608

Waiting on Oxfmt to implement additional features? Consider using @prettier/plugin-oxc in Prettier to gain some parsing speed in the meantime.

Features

• Support many kinds of file types
  • JS/TS(X): Supported by oxc_formatter
  • All file types supported by Prettier by default
• Faster alternative of Prettier CLI
  • Over 30× faster than Prettier’s experimental CLI without cache
• Experimental but usable features
  • Native sort-imports
  • Native sort-packagejson

Supported languages

• JS, JSX
• TS, TSX
• JSON, JSONC, JSON5
• YAML
• HTML, Angular, Vue, MJML
• Ember, Handlebars
• CSS, SCSS, Less
• GraphQL
• Markdown, MDX

WARNING

Note that the embeddedLanguageFormatting option is not fully supported in JS/TS files. And for now, it is disabled by default.

Installation

Run oxfmt directly at the root of your repository:

npm

$ npx oxfmt@latest

pnpm

$ pnpm dlx oxfmt@latest

yarn

$ yarn dlx oxfmt@latest

bun

$ bunx oxfmt@latest

deno

$ deno run npm:oxfmt@latest

Or save it to your package.json:

npm

$ npm add -D oxfmt

pnpm

$ pnpm add -D oxfmt

yarn

$ yarn add -D oxfmt

bun

$ bun add -D oxfmt

Command-line Interface

oxfmt CLI works like prettier --write . by default.

Formatting config options like --no-semi are not supported via CLI flags. We recommend setting these via the configuration file instead. This will ensure that the CLI and editor integrations always use the same settings.

Globs in positional paths are not expanded. (You can rely on your shell.) But !-prefixed exclude paths do support glob expansion.

See more details in the CLI reference.

Node.js API

oxfmt is also available via Node.js API: format() function.

import { format } from "oxfmt";
import type { FormatOptions } from "oxfmt";

const INPUT = `let a=42;`;
const options: FormatOptions = {
  semi: false,
};

const { code, errors } = await format("a.js", INPUT, options);
console.log(code); // "let a = 42"

System Requirements

• Node.js: >= 20.19.0 or >= 22.12.0
• Platforms: darwin-arm64, darwin-x64, linux-arm64, linux-x64, win32-arm64, and win32-x64

FAQs

What is the compatibility with Prettier?

For JS/TS files, we're tested against the v3.7.3 of Prettier.

For known differences, please see this discussion.

Oxfmt differences with Prettier · oxc-project/oxc · Discussion #14669
https://github.com/oxc-project/oxc/discussions/14669

Are there any limitations for configuration?

The following are NOT currently supported:

• prettier field in package.json
• File formats other than .json(c)
• Nested configs in sub directories
• overrides field
• Nested .editorconfig in sub directories
• experimentalTernaries and experimentalOperatorPosition option

Also, if printWidth is not specified, its default value is 100. This differs from Prettier's default 80.

Are Prettier plugins supported?

Currently, NOT supported.

However, for import sorting functionality, we provide experimental behavior based on eslint-plugin-perfectionist/sort-imports through the experimentalSortImports option.

And for prettier-plugin-packagejson, we have the experimentalSortPackageJson option, which is enabled by default.

See more details in the Configuration file reference.

Why are nested scripts and code blocks not formatted?

Currently, the embeddedLanguageFormatting option is off by default. Please set it to auto in your config file.