Biome: The All-in-One JavaScript Toolchain Replacing ESLint and Prettier

Biome is a fast, all-in-one toolchain for JavaScript and TypeScript that combines linting, formatting, and more in a single tool.

Why Biome?

• Speed: 10-100x faster than ESLint + Prettier
• One tool: Linting and formatting together
• Zero config: Works out of the box
• Rich diagnostics: Helpful error messages

Getting Started

# Install
npm install --save-dev @biomejs/biome

# Initialize config
npx biome init

# Format files
npx biome format --write .

# Lint files
npx biome lint .

# Both at once
npx biome check --write .

Configuration

// biome.json
{
  "formatter": {
    "indentStyle": "space",
    "indentWidth": 2
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "complexity": {
        "noForEach": "warn"
      }
    }
  }
}

Migration from ESLint

# Auto-migrate ESLint config
npx biome migrate eslint