Ship with
confidence.
Deterministic, offline-first package management for JavaScript. Built for monorepos.
Principled
Every decision in Yarn is measured against determinism, speed, usability, and monorepo-scale ergonomics.
Deterministic by default
A single yarn.lock produces byte-identical node_modules across machines, OSes, and CI providers. If it installs for you, it installs for them.
Plug'n'Play resolution
Skip node_modules entirely. PnP maps imports directly to the content-addressable cache — one install instead of thousands of file copies.
Offline-first cache
Every package you've ever resolved lives in the global cache. Subsequent installs — even in fresh clones — never hit the registry.
Workspaces, first-class
Monorepo primitives are native, not bolted on: topological builds, shared ranges, and constraint-based version policies across hundreds of packages.
Parallel everything
Fetch, link, and build stages run concurrently with bounded worker pools. yarn install saturates your CPU, not your patience.
Constraints engine
Enforce version policy declaratively across a monorepo. Prolog-style rules catch drift before it lands in main.
Performant
We don't just say we're fast - we prove it to ourselves. Our team runs automated tests every hour to catch any regression.
Full cold install (install-full-cold) of the Gatsby fixture — no cache, no lockfile, no node_modules. Median of multiple runs.
// source: repo.yarnpkg.com/benchmarks/gatsby/summary
Trusted
Yarn powers open-source projects and corporate repositories alike. You may have heard some of these names before?