--- section: cli-commands title: npm-ci description: Install a project with a clean slate --- # npm-ci(1) ## Install a project with a clean slate ### Synopsis ```bash npm ci ``` ### 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 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" ``` ### Description This command is similar to [`npm install`](/cli-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. It can be significantly faster than a regular npm install by skipping certain user-oriented features. It is also more strict than a regular install, which can help catch errors or inconsistencies caused by the incrementally-installed local environments of most npm users. In short, the main differences between using `npm install` and `npm ci` are: * The project **must** have an existing `package-lock.json` or `npm-shrinkwrap.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 any of the package-locks: installs are essentially frozen. ### See Also * [npm install](/cli-commands/npm-install) * [package-locks](/configuring-npm/package-locks)