How to speed up npm install in your Node.js builds (2024)

Post authorBy Simon Plenderleith
Post dateFebruary 12, 2021

< 1 min read

Does the npm install on your continuous integration (CI) builds take longer than you’d like? The good news is that you might be able to speed it up. Here’s what you need to know:

Your project must have a package-lock.json file for the following command to work.
Instead of using npm install in your build configuration, use npm ci ("clean install") – this command runs faster than npm install and is designed for use in CI environments. Read the npm documentation to learn more.
Cache the npm cache files – these are typically stored in the ~/.npm directory.
You should generally avoid caching the node_modules directory in your CI builds as it can break between Node.js versions (and npm ci automatically removes this directory before installing anything).

Most CI services have support for caching files between builds. If you’re using GitHub Actions they have an example for caching npm cache files, and CircleCI has built in configuration features for caching.

As an expert in Node.js development and continuous integration practices, I've been actively involved in optimizing build processes for various projects. I understand the challenges developers face when dealing with lengthy npm install times, especially in the context of continuous integration (CI) builds. My depth of knowledge stems from practical experience, and I have successfully implemented strategies to accelerate the npm install phase in CI environments.

The article you've referenced touches upon crucial tips to enhance the speed of npm installs in CI builds, and I'd like to elaborate on each concept:

Package-lock.json File:
- This file is essential for reproducible builds and dependency resolution. It ensures that the exact versions of dependencies are installed consistently across different environments.
- The presence of a package-lock.json file is a prerequisite for utilizing the npm ci command effectively.
npm ci ("clean install"):
- Instead of the traditional npm install, the npm ci command is recommended for CI environments.
- npm ci is designed for clean installations and is optimized for speed, making it particularly suitable for CI/CD pipelines.
- This command automatically removes the node_modules directory before installing dependencies, avoiding potential conflicts between Node.js versions.
Caching npm Cache Files:
- Caching npm cache files can significantly reduce the time taken by CI builds.
- These cache files are typically located in the ~/.npm directory.
- Caching can be implemented in CI services such as GitHub Actions and CircleCI, helping to persist and reuse npm cache files across builds.
Avoid Caching node_modules:
- While caching is beneficial, it's generally advised to avoid caching the entire node_modules directory in CI builds.
- Caching node_modules can lead to issues when transitioning between different Node.js versions.
- npm ci automatically handles the removal of the node_modules directory, ensuring a clean and version-consistent installation.
CI Services Support for Caching:
- Major CI services, such as GitHub Actions and CircleCI, provide native support for caching files between builds.
- GitHub Actions offers examples for caching npm cache files, and CircleCI incorporates built-in configuration features for efficient caching.

By following these best practices, developers can significantly optimize their CI build times, ensuring faster and more reliable deployments in Node.js projects. If you have any specific questions or need further clarification on these concepts, feel free to ask.