npm ci vs npm install command - Learn the differences

The npm install and npm ci commands are both used to install packages needed by your application.

But these two commands run the installation process with some differences.

Here are the differences between npm install and npm ci:

The npm install command

The npm install command is the default command used to install dependencies for your project.

Features of npm install include:

• You can install new dependencies not listed in your package.json file
• Controls the package.json file by adding and removing packages from the dependencies list
• Generates a package-lock.json or npm-shrinkwrap.json lock file

With npm install, you can install packages not yet included in your package.json file.

Suppose you have a package.json file with the following content:

{
  "name": "n-app",
  "version": "1.0.0",
  "main": "index.js",
  "dependencies": {
    "axios": "^0.27.2",
  },
}

Then, you install webpack as a dependency to your project as follows:

npm install webpack

Once the package is installed successfully, then the dependencies list will be updated:

{
  "name": "n-app",
  "version": "1.0.0",
  "main": "index.js",
  "dependencies": {
    "axios": "^0.27.2",
    "webpack": "^5.73.0"
  },
}

Furthermore, npm install also updates any dependency versions when available.

In the example above, you see the package.json listed webpack as a dependency version ^5.73.0.

The caret symbol (^) besides the version number means that when installing the package, npm will look for the latest minor version available from the registry and install it for you.

When you install webpack, the latest version is 5.73.0. But in the future, webpack may release a new version (5.75.0 for example) to introduce minor updates.

Instead of installing 5.73.0, npm will install 5.75.0 for you.

npm will also update the package-lock.json file accordingly, so that the next time you run npm install, npm knows that the latest version installed is 5.75.0.

The package-lock.json is a json file that keeps track of the exact dependency versions installed in your project.

The npm ci command

The npm ci command is short for clean-install. It was designed to install package dependencies in automated environments, such as when you do continuous integration for your project.

The npm ci command is available in npm v6 and above:

• You can’t install individual packages like with npm install
• npm ci never modifies your package.json and package-lock.json files
• The command requires package-lock.json or npm-shrinkwrap.json to be available. It will not run when a package lock file is not present

npm ci also deletes your node_modules folder if it’s present to ensure a clean install.

You can’t install individual dependencies as you can with npm install:

# 👇 error
npm ci webpack

When the versions listed under package.json and package-lock.json files do not match, npm ci will throw an error and stop the process.

This is different from npm install which will update package-lock.json to match package.json versions.

Because npm ci doesn’t check for the latest versions available, the command can run faster than npm install. In a project with many dependencies, npm ci can be twice faster than npm install.

When to use npm install vs npm ci?

The npm install command is used when you are developing the project. This is where you install new dependencies and update existing ones.

When you finished a project and want to run it in automated environments, the npm ci command should be used.

This ensures that your project will have the exact dependencies versions installed in testing and production environments.

To summarize: use npm install for development. Use npm ci when you run the project in automated environments.

Unlike npm install that seeks to update existing dependencies when possible, npm ci only install existing dependencies. This ensures you have reliable builds in continuous integration.

And now you’ve learned the differences between npm install and npm ci commands. Great work! 👍