Error [ERR_REQUIRE_ESM]: require() of ES Module not supported — how to fix

Error [ERR_REQUIRE_ESM]: require() of ES Module /app/node_modules/node-fetch/src/index.js from /app/index.js not supported.
Instead change the require of index.js in /app/index.js to a dynamic import() which is available in all CommonJS modules.

Quick fix: Quickest: install the last CommonJS version (npm i node-fetch@2, chalk@4, nanoid@3). Proper fix: switch your project to ESM ("type": "module" in package.json and import x from 'pkg'), or use const { default: fetch } = await import('node-fetch') inside an async function. Node 22.12+ / 20.19+ supports require() of ESM without top-level await.

What it means

Node has two module systems: CommonJS (require, module.exports) and ES modules (import, export). Many popular packages dropped CommonJS in recent major versions. Older Node versions can't load an ES module with require(), so they throw ERR_REQUIRE_ESM.

The path in the message tells you which package is ESM-only and which of your files is requiring it.

Fix 1: pin the last CommonJS version

Fastest if you don't want to touch your module setup:

For node-fetch, on Node 18+ you can drop the package entirely and use the built-in global fetch.

Fix 2: use dynamic import() from CommonJS

import() works in CommonJS files and returns a promise:

// index.js (CommonJS)
async function main() {
  const { default: chalk } = await import('chalk');
  console.log(chalk.green('ok'));
}
main();

Note the default for packages with a default export.

Fix 3: convert your project to ESM

In package.json:

{
  "type": "module"
}

Then replace require/module.exports:

import fetch from 'node-fetch';
import { readFile } from 'node:fs/promises';
import config from './config.js';     // relative imports need the extension
export function handler() {}

__dirname isn't defined in ESM; use import.meta.dirname (Node 20.11+) or path.dirname(fileURLToPath(import.meta.url)). Alternatively rename only some files to .mjs.

Fix 4: upgrade Node

Node 22.12+ and 20.19+ allow require() of ES modules by default, as long as the module doesn't use top-level await. Check with node -v. On older 22.x you could enable it with --experimental-require-module.

TypeScript compiles imports to require()

If you write import chalk from 'chalk' in TypeScript but get ERR_REQUIRE_ESM at runtime, tsc is emitting CommonJS. Either:

• emit ESM: set "module": "NodeNext", "moduleResolution": "NodeNext" in tsconfig.json and "type": "module" in package.json, or
• keep CommonJS and pin the CJS version of the dependency.

With ts-node, use node --loader ts-node/esm or switch to tsx, which handles both formats.

Jest

Jest's default CommonJS transform can't load ESM-only packages in node_modules. Options: pin the CJS version, add the package to transformIgnorePatterns exceptions so Babel transforms it, e.g. "transformIgnorePatterns": ["node_modules/(?!(chalk|nanoid)/)"], or move to Vitest which is ESM-native.

Last updated 2026-11-04.