🧰 Choosing the Right JavaScript Package Manager: npm vs Yarn vs pnpm vs Bun

When building JavaScript applications, your choice of package manager can have a big impact on development speed, reliability, and even how much space your dependencies take up.

With options like npm, Yarn, pnpm, and the rising star Bun, developers often ask:

“Which one should I use and why?”

In this post, I’ll break down what each package manager offers, where it shines, where it falls short, and when you should (or shouldn’t) use it.

📦 1. npm — The OG (Node Package Manager)

✅ Pros:

• Comes bundled with Node.js, so it’s always available out of the box.

• Huge community support and ecosystem.

• Familiar to almost every JavaScript developer.

❌ Cons:

• Slower installations compared to newer tools.

• Can duplicate a lot of dependencies across projects.

• Less efficient use of disk space.

• Limited monorepo support (requires external tools like Lerna).

🎯 Ideal For:

• Simpler projects or teams already using it.

• Projects where compatibility and stability matter more than performance.

🚫 Avoid If:

• You want maximum speed and disk efficiency.

• You’re managing a large monorepo.

🔧 Example:

Installing React:

npm install react react-dom

Running a script:

npm run build

Creating a package.json:

npm init -y

🧶 2. Yarn — The Deterministic Pioneer

Created by Facebook, Yarn was built to solve npm’s early shortcomings by offering speed, determinism, and better dependency resolution.

✅ Pros:

• Faster than npm, especially with caching.

• Deterministic installs via yarn.lock.

• Built-in support for monorepos (workspaces).

• Yarn 2+ (Berry) introduces innovative features like Plug’n’Play (PnP), which removes node_modules.

❌ Cons:

• Yarn 2+ is a significant shift from v1 (some breaking changes).

• Plug’n’Play can break some older packages that expect node_modules.

🎯 Ideal For:

• Projects needing monorepos or strict dependency management.

• Teams that want modern tooling with good performance.

🚫 Avoid If:

• You rely on legacy packages or tooling that assume traditional node_modules.

🔧 Example:

Installing React:

yarn add react react-dom

Running a script:

yarn build

Then:

yarn install

🌱 3. pnpm — Performance & Efficiency First

pnpm is all about speed and disk efficiency. It introduces a unique way of storing dependencies using hard links to a global store, saving space and avoiding duplication.

✅ Pros:

• Blazing fast installs.

• Uses up to 70% less disk space than npm/Yarn.

• Enforces strict dependency declarations (no more accidental access to undeclared packages).

• Excellent built-in support for monorepos.

❌ Cons:

• Slight learning curve due to its non-standard node_modules layout.

• Some tools (very few nowadays) might expect npm-style layouts.

🎯 Ideal For:

• Projects with large dependency trees.

• Monorepos and enterprise-scale applications.

• Teams that value speed and discipline

🚫 Avoid If:

• You’re using very old tooling or dependencies that don’t like non-standard layouts (rare these days).

🔧 Example:

Installing React:

pnpm add react react-dom

Running a script:

pnpm run build

Creating a pnpm workspace:

# pnpm-workspace.yaml packages: - 'apps/' - 'packages/'yam

Then:

pnpm install

⚡️ 4. Bun — The All-In-One Newcomer

Bun is more than a package manager — it’s an entire JavaScript runtime, bundler, and test runner, written in Zig. It’s designed from the ground up for speed.

✅ Pros:

• Ridiculously fast installs (and everything else).

• Bundler, transpiler, test runner, and runtime — all in one.

• TypeScript support out of the box.

• Modern APIs and first-class ES module support.

❌ Cons:

• Still evolving — some features and compatibility can be hit-or-miss.

• Not yet widely adopted or battle-tested like Node/npm.

• Some Node.js APIs and npm packages may not be fully supported.

🎯 Ideal For:

• Side projects, prototypes, and developers chasing the bleeding edge.

• Projects where speed matters above all else.

🚫 Avoid If:

• You need long-term production stability and full compatibility with the Node/npm ecosystem (for now).

🔧 Example:

Installing React:

bun add react react-dom

Running a script:

bun run build

Creating a new project:

bun i

Running a dev server:

bun dev

🧾 Quick Comparison Table — TL; DR

🧠 Final Thoughts: What Should You Use?

• 🟢 pnpm — Best all-around for performance, workspaces, and modern development.

• 🔵 Yarn — Great for monorepos and larger teams (just mind the Yarn 2+ learning curve).

• 🔴 npm — Reliable and compatible, good for legacy or simple apps.

• ⚡ Bun — For speed-loving early adopters and greenfield projects.

💬 Have a favorite or horror story with one of these? Let me know in the comments! And if you found this post helpful, give it a clap 👏 or share it with your fellow devs!