Yarn is a new package manager for JavaScript which can be used as substitute of NPM developed by Facebook and Google. I tried it out and want to share my first experiences with it which are not already presented at their homepage.


  • Can be used as substitute of NPM, it uses the package.json and the NPM registry
  • Creates a .lock file with the actual installed versions of the dependencies to ensure the next install will use the same
  • Performance, especially if there are already things cached
  • Some packages needs a flatten structure (e.g. eslint-config-airbnb with eslint-plugin-import)


  • It doesn’t execute postinstall scripts
  • Flatten most dependencies, keep the tree structure only for different dependency versions. Can broken things which expect tree structure (e.g. bin scripts)


The .lock file can make a difference by simplifying the deployment workflow and make it more stable and the disadvantages are more edge cases.

So it can be worth it to have a look at it, but its not the next big thing makes all smart until now.