What is the difference between npm install and npm run build?

Question

What is the difference between npm install and npm run build?

I have noticed in my project that sometimes npm starts failing when np

Answer 1

NPM in 2019

npm build no longer exists. You must call npm run build now. More info below.

TLDR;

npm install: installs dependencies, then calls the install from the package.json scripts field.

npm run build: runs the build field from the package.json scripts field.

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NPM Scripts Field

https://docs.npmjs.com/misc/scripts

There are many things you can put into the npm package.json scripts field. Check out the documentation link above more above the lifecycle of the scripts - most have pre and post hooks that you can run scripts before/after install, publish, uninstall, test, start, stop, shrinkwrap, version.

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To Complicate Things

• npm install is not the same as npm run install
• npm install installs package.json dependencies, then runs the package.json scripts.install
  • (Essentially calls npm run install after dependencies are installed.
• npm run install only runs the package.json scripts.install, it will not install dependencies.
• npm build used to be a valid command (used to be the same as npm run build) but it no longer is; it is now an internal command. If you run it you'll get: npm WARN build npm build called with no arguments. Did you mean to npm run-script build? You can read more on the documentation: https://docs.npmjs.com/cli/build

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Extra Notes

There are still two top level commands that will run scripts, they are:

• npm start which is the same as npm run start
• npm test ==> npm run test