---
title: npm-ci
section: 1
description: Clean install a project
---

### Synopsis

<!-- AUTOGENERATED USAGE DESCRIPTIONS -->

### Description

This command is similar to [`npm install`](/commands/npm-install), except it's meant to be used in automated environments such as test platforms, continuous integration, and deployment -- or any situation where you want to make sure you're doing a clean install of your dependencies.

The main differences between using `npm install` and `npm ci` are:

* The project **must** have an existing `package-lock.json`.
* If dependencies in the package lock do not match those in `package.json`,
  `npm ci` will exit with an error, instead of updating the package lock.
* `npm ci` can only install entire projects at a time: individual dependencies cannot be added with this command.
* If a `node_modules` is already present, it will be automatically removed before `npm ci` begins its install.
* It will never write to `package.json` or `package-lock.json`:
  installs are essentially frozen.

NOTE: If you create your `package-lock.json` file by running `npm install` with flags that can affect the shape of your dependency tree, such as
`--legacy-peer-deps` or `--install-links`, you _must_ provide the same flags to `npm ci` or you are likely to encounter errors.
An easy way to do this is to run, for example,
`npm config set legacy-peer-deps=true --location=project` and commit the
`.npmrc` file to your repo.

### Example

Make sure you have a package-lock and an up-to-date install:

```bash
$ cd ./my/npm/project
$ npm install
added 154 packages in 10s
$ ls | grep package-lock
```

Run `npm ci` in that project

```bash
$ npm ci
added 154 packages in 5s
```

Configure Travis CI to build using `npm ci` instead of `npm install`:

```bash
# .travis.yml
install:
- npm ci
# keep the npm cache around to speed up installs
cache:
  directories:
  - "$HOME/.npm"
```

### Configuration

<!-- AUTOGENERATED CONFIG DESCRIPTIONS -->

### See Also

* [npm install](/commands/npm-install)
* [package-lock.json](/configuring-npm/package-lock-json)
