Biome: Replace ESLint + Prettier with One Lightning-Fast Tool (2026)

Every JavaScript project eventually accumulates the same set of dev dependencies: ESLint for linting, Prettier for formatting, a pile of ESLint plugins, a shared config package, and a lint-staged setup that takes 10 seconds to run on pre-commit. It works. It’s also slow, complex, and requires constant maintenance.

Biome offers a different approach: one tool, one config file, sub-millisecond performance, and zero plugin dependencies. In 2026, it’s stable enough to replace ESLint + Prettier entirely in most TypeScript and JavaScript projects.

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What Is Biome?

Biome (formerly Rome) is a high-performance toolchain for JavaScript and TypeScript written in Rust. It provides:

• A formatter that produces Prettier-compatible output
• A linter with 200+ rules covering correctness, style, and performance
• An import organizer that sorts and deduplicates imports
• A language server for editor integration (VS Code, Neovim, etc.)

Everything runs in a single binary with no npm dependencies at runtime. A full lint + format pass on a 100,000-line codebase takes under 1 second.

---

Installation

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

# pnpm
pnpm add --save-dev --save-exact @biomejs/biome

# yarn
yarn add --dev --exact @biomejs/biome

Using --save-exact pins the version—Biome treats its output as deterministic, so unexpected upgrades shouldn’t change formatting.

Initialize a config file:

npx @biomejs/biome init

This creates biome.json:

{
  "$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
  "organizeImports": {
    "enabled": true
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true
    }
  },
  "formatter": {
    "enabled": true,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  }
}

---

Running Biome

# Format files
npx biome format --write .

# Lint files
npx biome lint .

# Lint + format in one pass
npx biome check --apply .

# Check without writing (for CI)
npx biome check .

The check command runs the linter, formatter, and import organizer together—one command does everything.

---

Configuration Reference

Biome’s biome.json handles everything that previously required .eslintrc, .prettierrc, and .editorconfig:

{
  "$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
  "organizeImports": {
    "enabled": true
  },
  "formatter": {
    "enabled": true,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100,
    "attributePosition": "auto"
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "double",
      "trailingCommas": "all",
      "semicolons": "always",
      "arrowParentheses": "always"
    }
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "correctness": {
        "noUnusedVariables": "error",
        "useExhaustiveDependencies": "warn"
      },
      "style": {
        "noVar": "error",
        "useConst": "error",
        "useTemplate": "error"
      },
      "suspicious": {
        "noConsoleLog": "warn",
        "noExplicitAny": "warn"
      },
      "performance": {
        "noAccumulatingSpread": "error"
      }
    }
  },
  "files": {
    "ignore": ["node_modules", "dist", ".next", "coverage"]
  }
}

Formatter Options

Option	Default	Description
indentStyle	"tab"	"tab" or "space"
indentWidth	2	Spaces per indent level
lineWidth	80	Max line length
quoteStyle	"double"	"single" or "double"
trailingCommas	"all"	"all", "es5", "none"
semicolons	"always"	"always" or "asNeeded"

---

Linting Rules

Biome ships with 200+ rules organized into categories. The recommended preset enables the most useful ones.

Key rule categories

Correctness — catches bugs:

{
  "correctness": {
    "noUnusedVariables": "error",
    "noUnusedImports": "error",
    "useExhaustiveDependencies": "warn",
    "noConstantCondition": "error",
    "noInvalidUseBeforeDeclaration": "error"
  }
}

Style — enforces patterns:

{
  "style": {
    "noVar": "error",
    "useConst": "error",
    "useTemplate": "error",
    "useShorthandFunctionType": "error",
    "useSingleVarDeclarator": "error"
  }
}

Suspicious — flags potentially problematic code:

{
  "suspicious": {
    "noExplicitAny": "warn",
    "noDoubleEquals": "error",
    "noConsoleLog": "warn",
    "noArrayIndexKey": "warn"
  }
}

Performance — prevents common performance anti-patterns:

{
  "performance": {
    "noAccumulatingSpread": "error",
    "noDelete": "warn"
  }
}

Inline rule suppression

// biome-ignore lint/suspicious/noExplicitAny: legacy API response
function parseResponse(data: any) {
  return data;
}

// biome-ignore format: intentional alignment
const matrix = [
  1, 0, 0,
  0, 1, 0,
  0, 0, 1,
];

---

Migration from ESLint + Prettier

Step 1: Remove ESLint and Prettier

npm uninstall eslint prettier \
  eslint-config-prettier \
  eslint-plugin-prettier \
  @typescript-eslint/eslint-plugin \
  @typescript-eslint/parser \
  eslint-plugin-react \
  eslint-plugin-react-hooks \
  eslint-plugin-import

# Remove config files
rm .eslintrc.js .eslintrc.json .prettierrc .eslintignore .prettierignore

Step 2: Install Biome

npm install --save-dev --save-exact @biomejs/biome
npx biome init

Step 3: Migrate your ESLint rules

Biome covers most common ESLint rules natively. Use the Biome migration tool:

npx @biomejs/biome migrate eslint --write
npx @biomejs/biome migrate prettier --write

This reads your existing .eslintrc and .prettierrc and generates equivalent biome.json configuration automatically.

Step 4: Update package.json scripts

{
  "scripts": {
    "lint": "biome check .",
    "lint:fix": "biome check --apply .",
    "format": "biome format --write ."
  }
}

Step 5: Update lint-staged (if using)

{
  "lint-staged": {
    "*.{js,ts,jsx,tsx,json}": "biome check --apply --no-errors-on-unmatched"
  }
}

---

CI Integration

# .github/workflows/ci.yml
name: CI

on: [push, pull_request]

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
          cache: npm
      - run: npm ci
      - run: npx biome ci .

biome ci is identical to biome check but exits with a non-zero code if any issues are found and outputs JSON-compatible logs for CI systems.

---

VS Code Extension

Install the Biome VS Code extension.

Configure VS Code to use Biome as the default formatter:

// .vscode/settings.json
{
  "editor.defaultFormatter": "biomejs.biome",
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "quickfix.biome": "explicit",
    "source.organizeImports.biome": "explicit"
  },
  "[javascript]": {
    "editor.defaultFormatter": "biomejs.biome"
  },
  "[typescript]": {
    "editor.defaultFormatter": "biomejs.biome"
  },
  "[typescriptreact]": {
    "editor.defaultFormatter": "biomejs.biome"
  },
  "[json]": {
    "editor.defaultFormatter": "biomejs.biome"
  }
}

The extension supports:

• Format on save
• Inline diagnostics for lint errors
• Quick fixes and auto-fix on save
• Import organization
• Code actions for rule suppression

---

Performance Comparison

The performance difference between Biome and ESLint + Prettier is significant:

Task	ESLint + Prettier	Biome
Lint 1,000 files	~8s	~0.2s
Format 1,000 files	~5s	~0.15s
Full check pass	~13s	~0.3s
Pre-commit hook (staged files)	2–5s	<100ms
CI lint job	30–60s	3–8s

Biome’s Rust implementation processes files in parallel without spawning Node processes, which accounts for most of the speedup.

---

What Biome Doesn’t Replace

Biome is not a complete replacement for every ESLint use case:

Still needs ESLint (or alternatives):

• Framework-specific rules (Next.js, Astro, SvelteKit)
• Accessibility rules (eslint-plugin-jsx-a11y)
• Complex custom rules written in JavaScript
• Storybook-specific linting

Biome’s current gaps:

• No support for .vue files (use ESLint for Vue projects)
• No CSS/SCSS linting (use Stylelint)
• No GraphQL linting
• Some TypeScript-specific ESLint rules aren’t ported yet

For most TypeScript/React/Next.js projects, these gaps won’t matter. For projects with heavy accessibility requirements, consider running both Biome (for performance) and eslint-plugin-jsx-a11y (for a11y rules).

---

Real-World Example: Next.js Project

Complete setup for a Next.js 14 project:

// biome.json
{
  "$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
  "organizeImports": { "enabled": true },
  "formatter": {
    "enabled": true,
    "indentStyle": "space",
    "indentWidth": 2,
    "lineWidth": 100
  },
  "javascript": {
    "formatter": {
      "quoteStyle": "double",
      "trailingCommas": "es5",
      "semicolons": "always"
    }
  },
  "linter": {
    "enabled": true,
    "rules": {
      "recommended": true,
      "correctness": {
        "useExhaustiveDependencies": "warn",
        "noUnusedVariables": "error",
        "noUnusedImports": "error"
      },
      "suspicious": {
        "noExplicitAny": "warn"
      }
    }
  },
  "files": {
    "ignore": [
      ".next",
      "node_modules",
      "public",
      "*.config.js",
      "*.config.ts"
    ]
  }
}

// package.json
{
  "scripts": {
    "lint": "biome check .",
    "lint:fix": "biome check --apply .",
    "format": "biome format --write ."
  },
  "devDependencies": {
    "@biomejs/biome": "1.9.4"
  }
}

---

Summary

Biome is the best choice for most TypeScript and JavaScript projects in 2026:

• Faster: 10-50x faster than ESLint + Prettier
• Simpler: One tool, one config, zero plugin dependencies
• Comprehensive: Linting, formatting, import organization in one pass
• Compatible: Prettier-compatible formatting, supports most ESLint rules
• Editor support: First-class VS Code extension with format-on-save

The migration from ESLint + Prettier takes under an hour with biome migrate. The performance gain in local development and CI is immediate.

Use Biome as your primary tool. If you need framework-specific rules that Biome doesn’t cover, keep a minimal ESLint config for just those rules.

Check out the Biome documentation and explore related tools in the DevPlaybook toolbox.