What is pnpm?

pnpm is a fast, disk‑space‑efficient package manager for JavaScript projects. It works like npm or Yarn, letting you install libraries (called “packages”) that your code needs, but it stores them in a special way that avoids duplicate copies.

Let's break it down

  • Package manager: a tool that downloads and manages code libraries.
  • pnpm: stands for “Performant npm”. It uses a global content‑addressable store, so identical files are saved only once.
  • Node_modules folder: pnpm creates a lightweight “symlink” tree that points to the shared store, making installations quicker and smaller.

Why does it matter?

  • Speed: installs are often 2‑3× faster because files are reused from the global store.
  • Less disk usage: projects share the same copy of a package, so you don’t waste space with many identical versions.
  • Strict node_modules layout: pnpm enforces a more accurate dependency tree, helping catch bugs that can appear with npm’s flat structure.

Where is it used?

  • Open‑source projects that want faster CI builds.
  • Companies with many JavaScript/TypeScript apps to save storage on build servers.
  • Individual developers who want quicker installs on their local machines.
  • It works with any Node.js project, including React, Vue, Angular, Next.js, and backend services.

Good things about it

  • Very fast installation and updates.
  • Saves a lot of disk space, especially in monorepos.
  • Predictable, strict dependency resolution reduces “works on my machine” issues.
  • Supports npm scripts, lockfiles, and works with most existing npm/Yarn workflows.
  • Good integration with tools like pnpm workspaces for managing multiple packages together.

Not-so-good things

  • Slight learning curve: the symlink approach can confuse developers used to npm’s flat node_modules.
  • Some older tools or scripts that expect a traditional node_modules layout may break.
  • Community size is smaller than npm’s, so fewer tutorials and third‑party plugins (though it’s growing).
  • Initial setup may require adding pnpm to CI pipelines and documentation for team members.