Comparisons

How Yarn compares to npm, pnpm, and bun.

Every package manager makes trade-offs. This page aims to be factual about where Yarn differs, and honest about where the others do well.

npm#

Where Yarn differs#

• Ghost dependency protection. npm uses a flat, hoisted node_modules layout that lets your code import packages you never declared as dependencies. Yarn’s default install strategy, PnP, enforces your declared dependency tree through a Node.js loader, eliminating this class of bugs entirely.

• Workspace tooling. Both support workspaces, but Yarn builds significantly more on top of them: constraints for linting your entire dependency tree, workspace profiles for shared dev dependency sets, the catalog: protocol for unified dependency ranges, and a task runner with cross-workspace dependencies.

• Built-in features. Yarn includes dependency patching, a task runner, and Node.js version management out of the box. With npm, these require separate tools.

• Version management. Yarn uses Yarn Switch to pin the exact package manager binary per project via the packageManager field. npm is bundled with Node.js and generally uses a single global version.

• Install speed. Yarn’s PnP mode avoids filesystem writes entirely, bringing typical installs down to a few seconds. Yarn tracks comparative benchmarks continuously on a public dashboard.

Where npm does well#

• Universality. npm ships with Node.js, so it requires zero setup. Every Node.js developer has it available from the start.

• Ecosystem assumptions. Some tools assume an npm-style node_modules layout, which means npm has fewer compatibility considerations to work around.

pnpm#

Where Yarn differs#

• Resolution approach. pnpm uses symlinks and a content-addressable store to build a nested node_modules tree. Yarn’s PnP avoids node_modules entirely and resolves dependencies via a Node.js loader, which is faster and enables features like zero-installs.

• Ghost dependency coverage. pnpm’s symlink-based isolation prevents many ghost dependencies, but its node_modules layout cannot correctly represent all dependency trees — particularly those involving peer dependencies. PnP handles these cases because it doesn’t rely on a filesystem tree to model the dependency graph.

• Monorepo tooling. Both have strong workspace support, but Yarn adds constraints for dependency tree linting, workspace profiles, the catalog: protocol, and a built-in task runner with cross-workspace dependencies.

• Node.js management. Yarn can manage Node.js as a regular project dependency via @builtin/node, locked in yarn.lock. pnpm provides pnpm env commands for managing Node.js versions, but not as a project dependency.

• Linker flexibility. Yarn supports three linker modes — PnP, pnpm-style symlinks, and traditional node_modules — all as first-class options from the same tool.

Where pnpm does well#

• Disk efficiency. pnpm’s content-addressable store with hard links is very space-efficient for projects that need a node_modules directory.

• Strictness without a loader. pnpm’s symlink approach provides meaningful ghost dependency protection without requiring a custom Node.js loader, which some teams prefer.

bun#

Where Yarn differs#

• Maturity. Yarn has been in production use since 2016 and has an extensive test suite. bun’s package manager is newer and still evolving.

• Correctness. bun prioritizes speed, sometimes at the expense of strict correctness. Yarn prioritizes both, with PnP enforcing dependency boundaries that bun’s flat node_modules layout does not.

• Monorepo features. Yarn provides a comprehensive monorepo toolkit: constraints, workspace profiles, task dependencies, and the catalog: protocol. bun’s workspace support is more limited.

• Independence. Yarn is community-maintained and not tied to any runtime or company. bun’s package manager is part of a VC-funded runtime, which means its roadmap is tied to bun’s commercial direction.

• Linker options. bun only produces node_modules. Yarn gives you three strategies to choose from.

Where bun does well#

• Raw speed. bun’s install speed is competitive, especially for cold installs on projects using node_modules.

• Unified runtime. If you already use bun as your runtime, its built-in package manager avoids needing a separate tool.