SyntaxError: Cannot use import statement outside a module — how to fix

SyntaxError: Cannot use import statement outside a module

Quick fix: Add "type": "module" to your package.json (or rename the file to .mjs). In the browser, use <script type="module">.

What it means

import only works in ES modules. Your file is being loaded as a classic script (browser) or as CommonJS (Node), where import is a syntax error.

In Node.js

Pick one:

// package.json
{
  "type": "module"
}

• or rename the file from .js to .mjs
• or keep CommonJS and use const x = require('x') instead of import

After switching to ESM, relative imports need extensions (./file.js) and __dirname is no longer defined. Use import.meta.dirname (Node 20.11+) instead.

In the browser

<script type="module" src="main.js"></script>

Modules must be served over HTTP(S). Opening the HTML file directly with file:// blocks module loading (you'll get a CORS error instead). Run a local server such as npx serve or python3 -m http.server.

In Jest

Jest uses CommonJS by default. Either use Babel (babel-jest with @babel/preset-env), ts-jest for TypeScript, or run Jest in native ESM mode:

node --experimental-vm-modules node_modules/jest/bin/jest.js

If the error comes from a package inside node_modules that ships only ESM, add it to transformIgnorePatterns exceptions so Babel transforms it:

transformIgnorePatterns: ['node_modules/(?!(some-esm-package)/)']

Alternatively, switch to Vitest, which supports ESM natively.

In TypeScript with ts-node

Set "module": "commonjs" in tsconfig.json, or use tsx instead of ts-node, which handles both module types.

Last updated 2026-10-27.