The Node.js runtime itself is distributed under the permissive MIT license, so it imposes almost no obligations, but the real license question for any Node.js project is the license status of the hundreds of npm dependencies in your node_modules tree, which is where compliance risk actually lives. A single npm install can pull in a thousand transitive packages, each with its own terms, and knowing your Node.js license posture means auditing that whole graph rather than just noting that Node is MIT. This guide covers both.
It helps to separate two things people conflate. There is the license of the Node.js platform, and there is the aggregate license situation of the code you install to run on it. The first is simple. The second is the work.
The Node.js runtime license
Node.js is released under the MIT license, one of the most permissive open-source licenses there is. It lets you use Node in commercial and closed-source products, modify it, and redistribute it, with essentially one obligation: preserve the copyright and license notice.
Node.js also bundles other components, most notably the V8 JavaScript engine (BSD-style license) and libuv (MIT). Their licenses are collected in the Node.js distribution's LICENSE file, and if you redistribute Node itself (for example, bundling it inside a desktop app or a container image you ship), you should carry that notice along. For the vast majority of teams who simply run their code on Node, the runtime's license is a non-issue. The obligations you actually need to manage come from your dependencies.
Auditing your npm dependency licenses
Your application's license exposure is the union of every package you install. Because npm dependency trees are deep and mostly transitive, you cannot eyeball this. Use tooling to enumerate it.
A quick local inventory:
# List every installed package and its license
npx license-checker --summary
# Or produce a full report to review
npx license-checker --json > licenses.json
license-checker walks node_modules and reports the declared license of each package. Run it against a clean install from your committed lockfile so the report reflects exactly what deploys. Skim the summary for anything outside your allowed set, then investigate the specific offenders.
The categories to watch in a Node.js project are the same as anywhere in open source:
- Permissive (MIT, ISC, BSD, Apache-2.0) dominate the npm ecosystem and are almost always fine for commercial use, subject to keeping attributions.
- Copyleft (GPL, LGPL, MPL) are rarer in npm but do appear, sometimes deep in a transitive chain. A GPL package pulled into a distributed product can create source-disclosure obligations.
- AGPL is the one most companies block outright because its network-use clause can reach SaaS deployments.
- Unlicensed or
UNLICENSEDpackages, and packages with no license field at all, are a real risk: absent a license you have no grant to use the code, so these need explicit resolution.
A frequent surprise is a permissive-looking direct dependency that drags in a copyleft or unlicensed transitive package several levels down. That is the case manual review misses and automated auditing catches.
Enforcing a license policy in CI
Auditing once tells you today's state. Enforcing in CI keeps it that way as dependencies change. The idea is to define an allowlist of acceptable licenses and fail the build when something outside it appears:
# Fail CI if a disallowed license shows up
npx license-checker --onlyAllow "MIT;ISC;BSD-2-Clause;BSD-3-Clause;Apache-2.0" \
--excludePrivatePackages
Wire that into your pipeline so a pull request introducing a banned or unknown license is caught before merge. Fixing a license problem at PR time is trivial; discovering it during a security review, a customer audit, or acquisition due diligence is expensive and sometimes deal-breaking.
For a durable record, generate a software bill of materials that captures component and license data together:
npx @cyclonedx/cyclonedx-npm --output-file sbom.json
Since the same dependency graph drives both vulnerability and license concerns, an SCA tool usually reports licenses alongside CVEs, which means one scan covers both. A tool such as Safeguard can flag a newly introduced copyleft or unlicensed npm package in a pull request and tie it to the direct dependency that pulled it in. For the fundamentals of dependency and license auditing, the Safeguard Academy has relevant material, and our broader write-up on OSS licenses covers the license families in more depth.
A pragmatic policy
You do not need a heavyweight process to start. A workable baseline for most commercial Node.js projects: auto-approve the common permissive licenses, require a human review for anything copyleft, block AGPL and unlicensed packages, and treat "no license field" as a build failure until resolved. Revisit the allowlist as new licenses appear.
Two honest caveats. First, license detection from package metadata is a strong first pass but can misread dual-licensed or custom-licensed packages, so route ambiguous cases to counsel. Second, this is engineering guidance, not legal advice; your legal team owns the final policy. The engineering job is to make the data visible and the policy enforceable.
FAQ
What license is Node.js released under?
The Node.js runtime is under the MIT license, a permissive license that allows commercial and closed-source use with attribution. It bundles other components such as V8 (BSD-style) and libuv (MIT), whose notices you should carry if you redistribute Node itself.
Do I need to worry about my npm dependencies' licenses?
Yes, and that is where the real work is. Your application inherits obligations from every installed package, including deep transitive ones. Audit the full tree with a tool like license-checker, since a permissive direct dependency can pull in a copyleft or unlicensed package underneath it.
How do I enforce license rules automatically?
Define an allowlist of acceptable licenses and run a checker in CI that fails the build when a package falls outside it. license-checker --onlyAllow does this, and an SCA tool can enforce a richer policy while also generating an SBOM for your records.
Which licenses should I be most careful about in npm?
AGPL packages, because their network-use clause can reach SaaS deployments, and packages with no license field or an UNLICENSED marker, because absent a grant you have no right to use the code. Copyleft licenses like GPL also warrant review before use in a distributed product.