Introduction

If you’ve ever wondered whether to run npm ci or stick with good old npm install, you’re in the right place. Here’s exactly what I learned.

What npm install really does

When I run npm install, here’s what’s happening:

Semver resolution and lockfile rewrites

First, npm reads my package.json, figures out the latest acceptable versions based on semver ranges, and checks against my package-lock.json. If anything doesn’t match exactly, it quietly rewrites the lockfile.

Incremental node_modules mutation

npm install tries to save time by only updating what’s necessary in node_modules. This incremental change is great for local development, especially for fast hot-reloading.

The npm ci difference

But what about npm ci? Here’s why it’s special:

Lockfile-first philosophy

npm ci completely trusts the lockfile. No version guessing, no automatic upgrades. Just precise, byte-for-byte consistency.

The “nuke & pave” node_modules step

Every time I run npm ci, it wipes out the entire node_modules folder before rebuilding it exactly according to the lockfile. This ensures absolute cleanliness.

Strict sync checks

If my package-lock.json and package.json aren’t perfectly synced, npm ci throws an error instead of guessing. That saved me countless hours chasing subtle bugs.

When I reach for npm ci (and when I don’t)

Here’s my personal rule-of-thumb:

• npm ci: Always in CI pipelines, Docker builds, and production deployments. It ensures deterministic, fast, and predictable outcomes.
• npm install: Daily local dev, especially when adding or upgrading dependencies frequently.

Common errors I still hit and quick fixes

Despite best practices, I still encounter occasional bumps:

• “package-lock.json is out of sync”: Quickly fixed by running npm install --package-lock-only.
• Native add-ons rebuild loop: Mitigated by caching the entire NPM cache directory between builds.

FAQ

• Does npm ci respect .npmrc proxies? Yes, it fully respects npm configuration files.
• Can I add a package with npm ci? Nope, use npm install for modifying dependencies.
• Is pnpm still faster? Usually, yes—but npm ci is plenty fast for most scenarios.

TL;DR

• Use npm ci for speed, consistency, and CI reliability.
• Use npm install locally for flexibility and incremental updates.
• Always commit and maintain a clean, synced package-lock.json.

Did you like this article? Then, keep learning:

• Understand differences in caching strategies for faster and more reliable builds
• Understand incremental node_modules updates and dependency management nuances with npm install
• Learn to use Bun in Laravel projects to speed up frontend dependency management
• Explore fast and efficient package manager Bun as an alternative to npm
• Learn to use Bun in PHP projects for faster frontend dependency handling
• Discover how to disable annoying npm funding messages in your projects
• Explore how Laravel simplifies error handling, helpful for managing npm and build errors
• Discover tools and best practices to ensure security, relevant to reliable package management