Complete Package Manager Comparison: npm vs pnpm vs yarn vs bun

Table of Contents

• Introduction
• Understanding Package Managers
• npm: The Default Choice
• pnpm: Efficient Disk Usage
• Yarn: Feature-Rich Alternative
• Bun: The Modern Contender
• Performance Comparison
• Feature Comparison
• Migration Guide
• Choosing the Right Tool
• Conclusion

Introduction

Choosing the right package manager for your JavaScript project can significantly impact your development workflow, build times, and disk space usage. With four major options available—npm, pnpm, yarn, and bun—each offering unique advantages, making an informed decision requires understanding their differences.

This comprehensive guide compares npm, pnpm, yarn, and bun across performance, features, compatibility, and use cases. Whether you’re starting a new project or considering migrating an existing one, you’ll learn which package manager best fits your needs and how to make the transition smoothly.

We’ll explore installation speeds, disk space efficiency, workspace support, and advanced features that can streamline your development process. By the end, you’ll have a clear understanding of when to use each tool and how to leverage their strengths.

Understanding Package Managers

Package managers handle dependency resolution, installation, and version management for JavaScript projects. They read your package.json file, resolve dependencies from the npm registry (or other sources), and install packages into node_modules.

Core Responsibilities

All package managers share these fundamental tasks:

# Installing dependencies
npm install
pnpm install
yarn install
bun install

# Adding a new package
npm install express
pnpm add express
yarn add express
bun add express

# Removing a package
npm uninstall express
pnpm remove express
yarn remove express
bun remove express

Lock Files

Each package manager generates a lock file to ensure reproducible installs:

• npm: package-lock.json
• pnpm: pnpm-lock.yaml
• Yarn: yarn.lock (v1) or .yarn/cache + .pnp.cjs (v2+)
• Bun: bun.lockb (binary format)

⚠️ Important: Always commit lock files to version control. They ensure all team members and CI/CD systems install identical dependency versions.

Registry Compatibility

All four package managers are compatible with the npm registry by default, meaning you can use the same packages regardless of which tool you choose. However, they differ in how they handle installation, caching, and dependency resolution.

npm: The Default Choice

npm (Node Package Manager) comes bundled with Node.js and has been the standard since 2010. It’s the most widely used package manager, with extensive documentation and community support.

Installation

npm is automatically installed when you install Node.js:

# Check npm version
npm --version

# Update npm to latest
npm install -g npm@latest

Key Features

Workspace Support: npm 7+ includes built-in workspace support for monorepos:

{
  "name": "my-monorepo",
  "workspaces": ["packages/*"]
}

Scripts: Run scripts defined in package.json:

npm run build
npm run test
npm start

npx: Execute packages without installing globally:

npx create-react-app my-app
npx eslint src/

Advantages

✅ Universal compatibility: Works everywhere Node.js works
✅ No additional installation: Comes with Node.js
✅ Extensive documentation: Well-documented with large community
✅ Mature ecosystem: Most tutorials and examples use npm
✅ Built-in security: npm audit for vulnerability scanning

Limitations

❌ Slower installs: Generally slower than alternatives
❌ Disk space: Creates duplicate dependencies in nested node_modules
❌ No content-addressable storage: Less efficient caching

Performance Characteristics

# Benchmark example (varies by project)
# npm install time: ~45 seconds
# Disk usage: ~500MB for a typical React app

When to Use npm

• New projects where simplicity matters
• Teams unfamiliar with other package managers
• Projects requiring maximum compatibility
• CI/CD pipelines already configured for npm

pnpm: Efficient Disk Usage

pnpm (performant npm) uses a content-addressable storage system and symlinks to dramatically reduce disk space usage. It’s particularly valuable for monorepos and projects with many dependencies.

Installation

# Using npm
npm install -g pnpm

# Using Homebrew (macOS)
brew install pnpm

# Using standalone script
curl -fsSL https://get.pnpm.io/install.sh | sh -

Key Features

Content-Addressable Storage: Packages are stored once globally and symlinked into projects:

# pnpm store location
pnpm store path
# Check store size
du -sh ~/.pnpm-store

Strict Dependency Resolution: Only dependencies listed in package.json are accessible, preventing phantom dependencies:

// ❌ This will fail with pnpm (good!)
// package.json only lists "express"
const lodash = require('lodash'); // Error: lodash not found

// ✅ Explicitly add dependencies
pnpm add lodash

Workspace Support: Excellent monorepo support with filtering and parallel execution:

# Run script in all workspaces
pnpm -r run build

# Run script in specific workspace
pnpm --filter @myorg/package-a run test

# Add dependency to specific workspace
pnpm --filter @myorg/package-a add express

Advantages

✅ Disk space efficiency: Can save 50-90% disk space
✅ Faster installs: Parallel downloads and efficient caching
✅ Strict resolution: Prevents phantom dependencies
✅ Monorepo optimized: Excellent workspace features
✅ npm compatible: Works with existing npm projects

Limitations

❌ Symlink complexity: Can cause issues with some tools
❌ Learning curve: Different behavior than npm
❌ Tool compatibility: Some tools don’t handle symlinks well

Performance Characteristics

# Benchmark example
# pnpm install time: ~20 seconds (2x faster than npm)
# Disk usage: ~150MB for same React app (70% reduction)

Configuration

# .npmrc or .pnpmrc
shamefully-hoist=false
strict-peer-dependencies=true
auto-install-peers=true

When to Use pnpm

• Monorepos with multiple packages
• Projects with many dependencies
• Disk space constraints
• Teams wanting stricter dependency management
• CI/CD environments where disk space matters

Yarn: Feature-Rich Alternative

Yarn was created by Facebook (now Meta) in 2016 to address npm’s performance and reliability issues. It has evolved into two versions: Yarn Classic (v1) and Yarn Berry (v2+).

Installation

# Yarn Classic (v1)
npm install -g yarn

# Yarn Berry (v2+) - recommended
corepack enable
corepack prepare yarn@stable --activate

Yarn Classic (v1)

The original Yarn, still widely used:

# Check version
yarn --version

# Install dependencies
yarn install

# Add package
yarn add express
yarn add -D typescript

# Remove package
yarn remove express

Key Features:

• Faster installs than npm
• yarn.lock for reproducible builds
• Workspace support
• Offline mode

Yarn Berry (v2+)

Modern Yarn with Plug’n’Play (PnP) architecture:

# Enable Yarn Berry
yarn set version stable

# Check version
yarn --version

Plug’n’Play: Eliminates node_modules entirely:

// .pnp.cjs contains dependency resolution
// No node_modules folder needed!

Zero-Installs: Commit .yarn/cache for zero-install CI:

# .gitignore adjustments
!.yarn/cache
!.yarn/releases

Plugins: Extend Yarn with plugins:

# Install plugin
yarn plugin import https://raw.githubusercontent.com/yarnpkg/berry/master/plugins/@yarnpkg/plugin-typescript.js

Advantages

✅ Fast installs: Parallel downloads and efficient caching
✅ Workspace support: Excellent monorepo features
✅ PnP mode: Fastest startup times (Yarn Berry)
✅ Rich CLI: More commands than npm
✅ Workspace protocols: Advanced dependency management

Limitations

❌ PnP compatibility: Some tools don’t support PnP
❌ Learning curve: Yarn Berry requires adaptation
❌ Two versions: Confusion between Classic and Berry

Performance Characteristics

# Yarn Classic
# Install time: ~25 seconds
# Yarn Berry (PnP)
# Install time: ~15 seconds
# Disk usage: ~100MB (no node_modules)

When to Use Yarn

• Teams already using Yarn
• Monorepos requiring advanced workspace features
• Projects wanting Plug’n’Play benefits
• Teams comfortable with Yarn’s ecosystem

Bun: The Modern Contender

Bun is a modern JavaScript runtime and toolkit that includes a fast package manager. It’s written in Zig and uses JavaScriptCore, making it significantly faster than Node.js-based alternatives.

Installation

# macOS/Linux
curl -fsSL https://bun.sh/install | bash

# Using npm
npm install -g bun

# Using Homebrew
brew install bun

Key Features

Extreme Speed: Written in Zig, Bun is incredibly fast:

# Install comparison
bun install    # ~5 seconds
npm install    # ~45 seconds

Built-in Runtime: Not just a package manager—it’s a complete runtime:

// Run TypeScript directly
bun run src/index.ts

// No need for ts-node or compilation step

Built-in Bundler: Bundle your code without webpack or esbuild:

bun build ./src/index.tsx --outdir ./dist

Built-in Test Runner: Test framework included:

import { test, expect } from "bun:test";

test("math works", () => {
  expect(2 + 2).toBe(4);
});

Package Management

# Install dependencies
bun install

# Add package
bun add express
bun add -d typescript

# Remove package
bun remove express

# Run scripts
bun run dev

Advantages

✅ Extreme performance: Fastest installs and runtime
✅ All-in-one: Runtime, bundler, test runner, package manager
✅ TypeScript support: Native TypeScript execution
✅ npm compatible: Works with existing npm projects
✅ Modern APIs: Web-standard APIs (fetch, WebSocket, etc.)

Limitations

❌ Newer project: Less mature than alternatives
❌ Compatibility: Some npm packages may not work
❌ Platform support: Best on macOS/Linux (Windows support improving)
❌ Ecosystem: Smaller community and fewer resources

Performance Characteristics

# Benchmark example
# bun install time: ~5 seconds (9x faster than npm)
# Runtime performance: 2-4x faster than Node.js

When to Use Bun

• New projects where performance is critical
• Projects wanting an all-in-one solution
• TypeScript-heavy projects
• Teams comfortable with cutting-edge tools
• Performance-critical applications

Performance Comparison

Let’s compare real-world performance metrics across different scenarios.

Installation Speed

Benchmark results for a typical React application with 200+ dependencies:

Disk Space Usage

Same React application installed with each manager:

Cold Start Performance

Time to start a development server:

# Benchmark: Next.js dev server startup
bun run dev        # ~800ms
pnpm run dev       # ~1.2s
yarn run dev       # ~1.5s
npm run dev        # ~2.0s

CI/CD Performance

Installation time in GitHub Actions (cold cache):

# Example GitHub Actions workflow
- name: Install dependencies
  run: |
    # npm: ~2 minutes
    # yarn: ~1.5 minutes
    # pnpm: ~1 minute
    # bun: ~30 seconds

💡 Tip: Use caching in CI/CD to improve performance regardless of package manager choice.

Feature Comparison

Core Features Matrix

Advanced Features

pnpm Workspace Filtering:

# Run tests only in changed packages
pnpm --filter "...{packages/**}[HEAD^1]" test

# Build dependencies first
pnpm --filter "@myorg/*" --filter "...@myorg/package-a" build

Yarn Workspace Protocols:

{
  "dependencies": {
    "package-a": "workspace:*",
    "package-b": "workspace:^",
    "package-c": "workspace:~"
  }
}

Bun Runtime Features:

// Native TypeScript support
import { serve } from "bun";

serve({
  fetch(req) {
    return new Response("Hello from Bun!");
  },
  port: 3000,
});

Migration Guide

From npm to pnpm

1. Install pnpm:

npm install -g pnpm

2. Remove node_modules and lock file:

rm -rf node_modules package-lock.json

3. Install with pnpm:

pnpm install

4. Update scripts (optional):

{
  "scripts": {
    "preinstall": "npx only-allow pnpm"
  }
}

From npm to Yarn

1. Install Yarn:

npm install -g yarn

2. Remove node_modules and lock file:

rm -rf node_modules package-lock.json

3. Install with Yarn:

yarn install

4. Update .gitignore:

node_modules/
yarn.lock
.yarn/cache  # For Yarn Berry

From npm to Bun

1. Install Bun:

curl -fsSL https://bun.sh/install | bash

2. Remove node_modules and lock file:

rm -rf node_modules package-lock.json

3. Install with Bun:

bun install

4. Update scripts:

{
  "scripts": {
    "dev": "bun run src/index.ts",
    "build": "bun build ./src/index.tsx --outdir ./dist"
  }
}

Monorepo Migration

Migrating a monorepo requires additional considerations:

# 1. Backup current setup
git commit -am "Backup before migration"

# 2. For pnpm: Update workspace configuration
# package.json
{
  "pnpm": {
    "overrides": {
      "some-package": "^1.0.0"
    }
  }
}

# 3. Install dependencies
pnpm install

# 4. Test all workspaces
pnpm -r run test

# 5. Update CI/CD configuration

⚠️ Important: Test thoroughly after migration. Some packages may behave differently, especially with pnpm’s strict dependency resolution.

Choosing the Right Tool

Decision Matrix

Choose npm if:

• Starting a new project and want simplicity
• Team is unfamiliar with other tools
• Maximum compatibility is required
• Working with legacy projects

Choose pnpm if:

• Managing a monorepo
• Disk space is a concern
• Want strict dependency management
• Need advanced workspace features
• CI/CD environments with space constraints

Choose Yarn if:

• Team already uses Yarn
• Need Plug’n’Play benefits (Yarn Berry)
• Want rich workspace features
• Comfortable with Yarn ecosystem

Choose Bun if:

• Starting a new project
• Performance is critical
• Want an all-in-one solution
• Using TypeScript extensively
• Comfortable with cutting-edge tools

Project Size Considerations

Small Projects (< 50 dependencies):

• Any package manager works well
• npm is simplest choice
• Bun offers best performance

Medium Projects (50-200 dependencies):

• pnpm or Yarn recommended
• Better disk space efficiency
• Faster installs

Large Projects (200+ dependencies):

• pnpm highly recommended
• Significant disk space savings
• Advanced workspace features

Monorepos:

• pnpm or Yarn Berry recommended
• Best workspace support
• Efficient dependency management

Team Considerations

Team Experience:

• New teams: npm (easiest to learn)
• Experienced teams: pnpm or Yarn
• Performance-focused: Bun

CI/CD Requirements:

• Disk space limited: pnpm or Yarn Berry
• Speed critical: Bun
• Standard: Any works

Compatibility Needs:

• Maximum compatibility: npm
• Modern tools: pnpm, Yarn, Bun
• Legacy support: npm or Yarn Classic

Conclusion

Each package manager—npm, pnpm, yarn, and bun—offers unique advantages suited to different project needs and team preferences. npm remains the most compatible and widely supported option, while pnpm excels in monorepos and disk efficiency. Yarn provides rich features and Plug’n’Play capabilities, and Bun offers unmatched performance with an all-in-one toolkit.

For most projects, pnpm strikes an excellent balance between performance, disk efficiency, and advanced features, making it an ideal choice for modern JavaScript development. However, if you’re starting fresh and performance is paramount, Bun provides the fastest experience with additional runtime benefits.

When making your decision, consider your project size, team experience, CI/CD constraints, and long-term maintenance needs. You can always migrate between package managers, but choosing the right one from the start saves time and avoids compatibility issues.

Next Steps

• Experiment with different package managers in a test project
• Benchmark installation times for your specific dependencies
• Consider your team’s familiarity and training needs
• Evaluate CI/CD performance with each option
• Check compatibility with your existing tooling

For more JavaScript and Node.js insights, check out our guides on JavaScript array methods and Node.js best practices. If you’re working with TypeScript, our TypeScript cheatsheet covers advanced type patterns that work well with any package manager.

Resources:

• npm Documentation
• pnpm Documentation
• Yarn Documentation
• Bun Documentation