pnpm vs npm vs Yarn Compared! Differences in Speed and Disk Usage

How They Work: Storage and Dependency Resolution

The biggest difference among the three lies in how dependencies are installed. npm copies packages into a flattened node_modules. While it includes optimizations to reduce duplication, it basically places the actual files in each project. Yarn Classic uses a similar layout, with a design that prioritizes stability and compatibility.

pnpm uses a content-addressable store. As explained in the official pnpm documentation (https://pnpm.io/motivation), the actual package files are kept in a single global location. Only hard links are placed in the project. Deduplication is thorough, and the structure prevents invalid references.

Yarn Berry offers an approach called Plug’n’Play. It creates no node_modules and references compressed archives directly. It is designed to reduce the number of installed files and enforce stricter resolution. However, incompatibilities can occur with tools that assume traditional resolution.

Strictness of dependency resolution also differs. Many packages work under the lenient resolution of npm and Yarn Classic. pnpm and Yarn Berry do not allow undeclared references. While this helps eliminate phantom dependencies, older packages may require additional declarations.

Speed Comparison:

First-Time and Repeat Install Trends

Speed varies with conditions, but the trends are clear. First-time installs depend on network speed and extraction. In the official pnpm benchmarks (https://pnpm.io/benchmarks), large projects often complete faster than with npm. Parallel fetching and reuse of the store contribute to this.

The gap widens on the second and later installs. If the content is already in the store, pnpm only needs to create links. Many cases finish in seconds. npm has become faster through effective use of its cache, but per-project copying remains. Yarn Berry’s Plug’n’Play requires little extraction and is among the fastest for reinstalls.

In practice, the difference is most noticeable in continuous integration. With npm, restoring the cache is key. With pnpm, sharing the store reduces the amount that needs to be restored. It works well with layer reuse in Docker builds. In monorepos, Yarn Berry’s zero-installs workflow can be effective in some cases.

One caveat is to keep measurement conditions consistent. Results change depending on the presence of a lockfile and the state of the cache. Concurrency and machine performance also have an effect. Treat published figures as a guide, and average three runs in your own project for a reliable comparison.

Disk Usage: Deduplication Effects and Examples

The difference in size grows as the number of projects increases. npm can use hundreds of megabytes per project. It is not uncommon for ten projects to reach several gigabytes. Yarn Classic shows a similar trend.

pnpm keeps usage down by sharing the actual files. Community testing reports that ten typical React-based projects took about 3GB with npm compared to about 1.2GB with pnpm. The benefit shrinks when many different versions are used, but organizations using similar packages see large savings.

Yarn Berry’s Plug’n’Play stores pre-extraction compressed archives. It is often smaller than the node_modules layout. With zero-installs, repository size grows because the store is included. You need to consider the trade-off between fetch time and repository size.

Cache maintenance also matters in daily operation. npm uses npm cache verify to keep the cache healthy. pnpm uses pnpm store prune to remove unneeded content. Yarn uses yarn cache clean to tidy its cache. Clean regularly to prevent bloat.

Compatibility and Migration:

Lockfiles and Toolchain Notes

For compatibility, npm is the safest choice. It is bundled with Node.js and supported by almost all tools. No additional configuration is needed. It causes little friction for small client work or distributing learning materials.

Migrating to pnpm requires recreating the lockfile. You can import other lockfile formats with pnpm import. For full reproducibility, operating with pnpm install --frozen-lockfile is essential. Changes to continuous integration configuration are also required.

A pnpm-specific challenge is strict handling of peer dependencies. Conflicts can occur with combinations of React 18 and older plugins. Work around them with pnpm.overrides or hoisting and allowlist settings. Checking beforehand with pnpm install --strict-peer-dependencies is effective.

Yarn Berry requires verifying tool support. Compatibility issues with the extraction-free approach remain for React Native and Electron. A fallback is to set nodeLinker back to node-modules. For gradual migration, staying on the Classic maintenance line can also be a reasonable choice.

Choosing by Use Case:

Deciding by Scale and Team Setup

npm suits personal development and small projects. There are few environment differences, and solutions to questions are abundant. It has the advantage of working regardless of the delivery environment. It is a good baseline when you want to keep the learning burden low.

pnpm is strong for working on multiple projects in parallel and for monorepos. Sharing the store saves space and time. It has built-in workspaces support, which works well with splitting code into packages. It suits organizations that want to maintain quality through strict resolution.

Yarn Berry is a candidate for large monorepos and advanced control. Its constraints feature enables version enforcement for dependencies. A zero-installs workflow that skips fetching is also possible. It assumes a team that can accept the configuration and learning costs.

The toolchain perspective is also essential. Pinning the package manager version with Corepack is effective. Combined with Node.js version management via Volta, reproducibility improves. In Docker, order the copying of the lockfile and manifest to promote layer reuse.

Editorial Opinion

We evaluate reproducibility and operational overhead more highly than install speed alone. We see pnpm as strong for running multiple projects in parallel, with fewer malfunctions thanks to strict dependency resolution. We rate npm as the baseline for small-scale development, with the advantages of being standard equipment and having abundant information.

The pitfall is that old code relying on phantom dependencies will not run on pnpm. We see cases where continuous integration fails due to configuration differences not found in the official documentation, taking time to investigate. When migrating, reviewing dependency checks and link and hoisting allowlist settings is essential.

We expect store-based efficiency in the style of pnpm to become mainstream over the next 1 to 3 years. The rise of Deno and Bun seems likely to drive further integration of package management. We see opportunities for Yarn in strengthening features for large monorepos.

References

• Official pnpm Documentation
• pnpm Motivation
• pnpm Benchmarks
• npm Documentation
• Yarn Documentation
• Official Node.js Site