JavaScript has never had more choices for managing dependencies. In 2025 developers can pick between npm, yarn, pnpm and the newcomer Bun. Each tool promises faster installs, deterministic builds and better developer experience, but the right choice depends on your project’s size and priorities. This article compares the strengths and weaknesses of the major package managers so you can choose confidently.

Table of Contents

• 1. Overview of Popular Package Managers
• 2. npm: Strengths and Weaknesses
• 3. Yarn and pnpm
• 4. Bun: The New Challenger
• 5. Choosing the Right Tool
• 6. Conclusion

1. Overview of Popular Package Managers

A package manager downloads and installs the libraries your project needs. For many years npm shipped with Node.js and was the only choice. Yarn arrived with faster installs and a lockfile that kept dependency trees consistent. pnpm then introduced a unique content-addressable store that saves disk space. Recently,Bun has emerged, written in Zig and aiming to replace both your package manager and bundler.

2. npm: Strengths and Weaknesses

npm is still the default for many projects because it’s included with Node.js. It boasts the largest registry and works on every hosting environment. However, npm’s flat node_modules structure duplicates dependencies, wasting disk space on large monorepos. Install times can also be slower compared to newer tools. npm’s v10 release introduced improvements in performance and caching, but it remains slower than its rivals on cold installs.

# install dependencies with npm
npm install

3. Yarn and pnpm

Yarn was created by Facebook to address npm’s speed and determinism issues. It introduced a lockfile and offline caching, plus commands likeyarn workspaces for monorepos. Yarn 2+ swapped out thenode_modules folder for Plug’n’Play (PnP) but had limited adoption. It remains popular for its zero‑install caching and elegant CLI.

pnpm takes a different approach. Instead of duplicating files, it stores all packages in a global content‑addressable cache and uses hard links into project folders. This means multiple projects share the same dependency versions on disk, saving gigabytes on large codebases. pnpm also features strict version resolution and faster installs.

# install dependencies with pnpm
pnpm install

# add a package
pnpm add react

4. Bun: The New Challenger

Bun is an all‑in‑one runtime, bundler and package manager built with the Zig programming language. It boasts lightning‑fast cold installs and supports npm’s package ecosystem. Bun’s package manager uses a binary lockfile for speed and includes first‑class TypeScript and JSX support. Because Bun includes a bundler and test runner, it can replace several tools in your stack. The downside is that it is still young; some packages may not work out of the box, and ecosystem tooling like deployment providers are catching up.

# install dependencies with Bun
bun install

5. Choosing the Right Tool

The best package manager depends on your priorities. For maximum compatibility and ease of use, npm is a safe choice. If you run a monorepo or want deterministic installs with workspace support, yarn or pnpm can improve speed and consistency. Choose pnpm when disk space matters or you maintain many similar projects. Bun is attractive for new projects that value speed and are willing to adopt its runtime and bundler features. Whichever you pick, lock your dependencies and watch for updates—tooling evolves quickly.

6. Conclusion

Package managers have come a long way since npm first appeared. Today’s tools offer faster installs, deterministic lockfiles and better support for monorepos. By understanding the differences between npm, yarn, pnpm and Bun you can choose the package manager that aligns with your workflow. The JavaScript ecosystem moves quickly, so keep an eye on updates and don’t be afraid to experiment on smaller projects before committing to a new tool in production.