Specify Node Version in package.json
To set up your project's Node.js version in the package.json
, use the engines
field:
{
"engines": {
"node": ">=14.0.0"
}
}
You can use different version ranges:
>=14.0.0 <15.0.0
: Keeps it between specific versions.^14.0.0
: Compatible with version 14 and up to the next major one.~14.0.0
: Allows patches for version 14.
To enforce version requirements, add a .npmrc
file in your project directory with engine-strict=true
inside.
You can also create a script to check version compatibility. Make a file called check-node-version.js
to compare your current Node version with the one in package.json
.
Add this check to your scripts in package.json
:
{
"scripts": {
"start": "node check-node-version.js && node index.js",
"check-version": "node check-node-version.js"
}
}
Setting the Node.js version in package.json
helps your project run smoothly and avoids issues with incompatible Node versions.
.nvmrc for Node Version Management
The .nvmrc
file offers a simple way to manage Node versions using Node Version Manager (NVM).
Create a file named .nvmrc
in your project's root directory with the required Node.js version:
14.15.0
With .nvmrc
set up, run nvm use
when entering your project directory to switch to the specified Node version automatically.
To check your current Node version after switching, use node -v
.
Using the .nvmrc
file helps you and your team stay on track with the correct Node version, allowing you to work confidently knowing your versions are aligned.
Custom Script for Version Check
Create a custom Node.js script to verify the specified Node version against the running version:
- Install semver:
npm install semver
- Create
check-node-version.js
:
const semver = require('semver');
const engines = require('./package.json').engines;
const currentVersion = process.version;
if (!semver.satisfies(currentVersion, engines.node)) {
console.error(`Node.js version mismatch: Expected ${engines.node} but you're on ${currentVersion}.`);
process.exit(1);
} else {
console.log(`Node.js version ${currentVersion} matches the specified range: ${engines.node}.`);
}
- Update
package.json
:
{
"scripts": {
"start": "node check-node-version.js && node index.js",
"check-version": "node check-node-version.js"
}
}
This script checks that the Node version matches your project's requirements before starting, helping to prevent version-related issues.

.npmrc for Error Enforcement
The .npmrc
file can enforce version constraints set in your package.json
using the engines
field.
Create a .npmrc
file in your project's root directory with:
engine-strict=true
This ensures any version mismatch between your system's Node.js or npm versions and those in package.json
triggers an error message.
When running npm install
, if your installed Node or npm versions don't meet your specifications, the engine-strict policy stops the process and outputs an error. This alerts you to potential environment issues early and saves time by immediately pointing out areas needing attention.
The .npmrc
file acts as an enforcer, catching version discrepancies early and keeping your projects on track.
Setting the Node.js version in your project creates a stable environment that supports smooth development and collaboration. By specifying the required Node.js version, you can:
- Ensure compatibility across different environments
- Improve stability by avoiding unexpected behavior due to version differences
- Enhance reproducibility of bugs and issues
- Maintain consistent performance across development and production environments
Remember, different Node.js versions can have varying features and capabilities. By specifying a version, you're not just setting a number – you're establishing a foundation for your project's reliability and consistency.
- Semantic Versioning 2.0.0. SemVer. 2013.
- Node Version Manager. GitHub. 2022.
- npm-package.json. npm Docs. 2022.