pnpm Beats npm in Monorepos, but npm Remains Simpler for Small Projects

A technical analysis argues that pnpm's advantage over npm is not universal but depends heavily on project structure. In monorepos with multiple workspace packages, npm can store duplicate copies of shared dependencies like React or lodash, while pnpm uses a global content-addressable store with symlinks to keep only one copy on disk. This difference becomes significant as the number of packages in a monorepo grows, saving both disk space and install time in CI environments with warm caches. However, for small single-package projects, the install time difference between the two tools is negligible since there is no duplication to eliminate. Migrating to pnpm also carries hidden costs, including incompatibility with existing CI scripts, Docker configurations, and tooling built around npm's lockfile format.