Why you should switch from NPM to Yarn, the differences, and a comparison of commands (with a cheatsheet)

npm-vs-yarn.md

Switching From NPM to Yarn

We've switched to Yarn because it was built in collaboration with Facebook, Google, and others. We're primarily using it for how much faster it is though. Yarn supports emojis, is extremely faster, has automatic shrinkwrapping (hence the yarn.lock file), and much better security.

You can find out why a package is installed (and what's using it):

yarn why <package-name>

And even list outdated packages that you might want to upgrade:

yarn outdated

You can see all of the differences here as well.

Moving on! When you start a fresh project, you'll typically run this command:

npm install

With Yarn, all you need to run is this command:

yarn

A yarn.lock file will be created after you do this. Don't delete this file though, it tells Yarn exactly what version of each dependency is installed so you have consistent installs across machines.

Installing Packages

When you want to add a package in npm, you would do this:

npm install <my-package> --save

With Yarn, all we need to do is:

yarn add <my-package>

There's no need for a --save flag, it will automatically add the package to the package.json file.

NOTE: This only applies to standard dependencies, if you need to save a package as a developer dependency, please keep reading.

With npm, if you want to save a package as a developer dependency, you would add the --save-dev flag. With Yarn, you can do this like so:

yarn add <my-dev-package> --dev

Installing Global Packages

With npm, if you want a package available globally on the system, you would run:

npm install -g <my-global-package>

There's other ways to run the same command, e.g.:

npm install <my-global-package> --global
npm i -g <my-global-package>

But for the sake of this document, I'm assuming you either know the shorthand way of doing things, or already have a preferred method. Anyways, when it comes to Yarn, this is how you install a package globally:

yarn global add <my-global-package>

Updating Packages

With npm, when you want to update all of the packages you run:

npm update --save

And actually, it's really rare to use the --save flag here.

With Yarn, we just have to run:

yarn upgrade

Cheat Sheet

NPM	Yarn
npm install	yarn
npm install <my-package> --save	yarn add <my-package>
npm install <my-dev-package> --save-dev	yarn add <my-dev-package> --dev
npm uninstall <my-package> --save	yarn remove <my-package>
npm uninstall <my-package> --save-dev	yarn remove <my-package> --dev
npm update	yarn upgrade
npm install <my-package>@latest --save	yarn add <my-package>
npm install <my-global-package> --global	yarn global add <my-global-package>
npm init	yarn init
npm outdated	yarn outdated
npm link	yarn link
npm login	yarn login
npm logout	yarn logout
npm publish	yarn publish
npm run	yarn run
npm cache clean	yarn cache clean
npm test	yarn test