Yarn - JavaScript Package Manager

Yarn is an alternative package manager for JavaScript that works with Node.js.
It is designed to be faster, more reliable, and more secure than npm, while still being compatible with the same package ecosystem.

Installation

On macOS with Homebrew:

brew install yarn

Check version:

yarn -v

Basic Commands

Initialize a new project:

yarn init -y

Install dependencies from package.json:

yarn install

Add a new dependency:

yarn add react

Add a development dependency:

yarn add --dev webpack

Remove a dependency:

yarn remove react

Upgrade a dependency:

yarn upgrade react@latest

Run scripts from package.json:

yarn start
yarn build

Global Packages

Add a global package:

yarn global add typescript

Check global packages:

yarn global list

Remove a global package:

yarn global remove typescript

Workspaces

Yarn supports monorepos with workspaces.

Add to root package.json:

{
  "private": true,
  "workspaces": [
    "packages/*"
  ]
}

Install dependencies across all workspaces:

yarn install

Comparison with npm

Feature	npm	yarn
Default with Node.js	✅ Yes	❌ No (needs install)
Speed	Slower (sequential installs)	Faster (parallel installs, cache)
Lockfile	`package-lock.json`	`yarn.lock`
Workspaces	Supported (npm v7+)	Native support, very stable
CLI command prefix	`npm run script`	`yarn script` (shorter syntax)

Integration with nvm

If you switch Node.js versions with nvm, you may need to reinstall global Yarn:

nvm install node --reinstall-packages-from=$(nvm current)

Useful Commands

Clear cache:

yarn cache clean

Check outdated packages:

yarn outdated

Audit for vulnerabilities:

yarn audit