Node.js "Cannot find module 'node-fetch'" (ESM-only v3) in CI

node-fetch v3+ is published as ESM only. CommonJS code that require("node-fetch") either cannot resolve it or throws ERR_REQUIRE_ESM, breaking the build.

What this error means

After upgrading node-fetch, a CommonJS project fails on require("node-fetch") with a module-not-found or ERR_REQUIRE_ESM error in CI.

node

Error [ERR_REQUIRE_ESM]: require() of ES Module
/work/repo/node_modules/node-fetch/src/index.js from
/work/repo/src/http.js not supported.
  code: 'ERR_REQUIRE_ESM'

Common causes

node-fetch v3 dropped CommonJS

Version 3 ships ESM only. A CommonJS project that upgrades can no longer require it synchronously.

Native fetch makes node-fetch unnecessary

Modern Node has a global fetch. Keeping node-fetch at all is often avoidable and the source of the ESM mismatch.

How to fix it

Use the built-in global fetch

Drop the dependency entirely on Node 18+, which provides fetch globally.

src/http.js

// remove node-fetch import
const res = await fetch('https://example.com');
const data = await res.json();

Or pin node-fetch v2 for CommonJS

If you must keep node-fetch in a CommonJS project, pin v2, which still ships CommonJS.

Terminal

npm install node-fetch@2

How to prevent it

Prefer the global fetch on Node 18+ and remove node-fetch.
Read changelogs for ESM-only majors before upgrading.
Keep one module system across the project.