NPM, PNPM, Yarn & Bun – What They Are and Which One You Should Use

What is a Package Manager?

When you build a JavaScript app, you don’t have to write every single feature from scratch. Many common features (like JSON Web Tokens, encryption, sorting) are already available as packages.

A package manager is a tool that:

Installs these packages in your project
Updates them when needed
Keeps track of their versions and dependencies

Without it, you’d manually download code from GitHub and place it in your project, which is slow and error-prone.

1️⃣ NPM (Node Package Manager)

Default package manager that comes with Node.js.

Pros:
- Largest package ecosystem in the world
- Official support and regular updates
- Zero setup – works out of the box
Cons:
- Slower compared to others
- node_modules folder can get huge and bloated

Best for: Stability, wide support, and when you don’t want extra setup.

2️⃣ Yarn

Created by Facebook (Meta) to make installs faster.

Uses parallel installation, so packages install quicker.

Pros:
- Faster than NPM
- Has Workspaces for monorepos (managing multiple projects together)
- Manages dependencies more efficiently
Cons:
- You can’t mix Yarn and NPM lock files in the same project

Best for: Large projects, monorepos, and when speed matters.

3️⃣ PNPM

Stands for Performant NPM.

Saves disk space by storing packages globally and using symlinks instead of making copies in every project.

Pros:
- Very fast installs
- Huge disk space savings
- Excellent Workspaces support for monorepos
Cons:
- Not always supported everywhere (extra config needed for some deployments)

Best for: Developers managing many projects or monorepos who want speed + space savings.

4️⃣ Bun

A new, blazing-fast JavaScript runtime that can replace Node.js.

More than just a package manager – it also includes:

A built-in bundler
Test runner
AWS SDK support out of the box
Pros:
- Extremely fast package installs (feels instant)
- Can replace multiple tools at once
Cons:
- New and less battle-tested
- Possible compatibility issues with older packages

Best for: Speed-focused projects and experimenting with new tech.

💡 Final Advice

For beginners → Start with NPM (stable, well-supported).
For large projects → Use Yarn or PNPM.
For experiments and max speed → Try Bun.