How to fix ReferenceError: __filename is not defined in ES module scope in Node.js

Node.jsINTERMEDIATEMEDIUM

This error occurs when trying to use the CommonJS global __filename in an ES module. ES modules use a different approach to access file paths and do not provide __filename by default.

What this error means

The __filename global variable is a CommonJS feature that provides the absolute path of the currently executing file. When Node.js runs in ES module mode (either through "type": "module" in package.json or using .mjs file extensions), these CommonJS globals are not available. This is by design - ES modules follow the ECMAScript specification which doesn't include these Node.js-specific globals, aiming for better compatibility with browser environments and standardized JavaScript. The error occurs when your code attempts to reference __filename in an ES module context.

How to fix "ReferenceError: __filename is not defined in ES module scope"

1Verify you're using ES modules

Check your package.json for "type": "module" or verify your file has a .mjs extension:

json

{
  "type": "module"
}

If you see this, you're in ES module mode and need to use the ES module alternatives.

2Use import.meta.filename for Node.js 20.11.0+

If you're running Node.js version 20.11.0 or higher, you can use the modern built-in properties:

javascript

console.log(import.meta.filename);  // Current file path
console.log(import.meta.dirname);   // Current directory path

This is the simplest and recommended approach for modern Node.js versions. Check your version with node --version.

3Use fileURLToPath for older Node.js versions

For Node.js versions before 20.11.0, manually create __filename and __dirname using import.meta.url:

javascript

import path from 'path';
import { fileURLToPath } from 'url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Now you can use __filename and __dirname as before
console.log(__filename);
console.log(__dirname);

This replicates the CommonJS behavior in ES modules.

4Create a reusable utility module

If you need __filename/__dirname across many files, create a shared utility:

javascript

// utils/paths.js
import path from 'path';
import { fileURLToPath } from 'url';

export function getDirname(importMetaUrl) {
  const __filename = fileURLToPath(importMetaUrl);
  return path.dirname(__filename);
}

export function getFilename(importMetaUrl) {
  return fileURLToPath(importMetaUrl);
}

Then use it in your files:

javascript

import { getDirname, getFilename } from './utils/paths.js';

const __dirname = getDirname(import.meta.url);
const __filename = getFilename(import.meta.url);

5Alternative: Switch back to CommonJS

If you don't need ES modules, you can switch back to CommonJS:

1. Remove "type": "module" from package.json
2. Rename .mjs files to .js (or use .cjs extension)
3. Replace import/export with require()/module.exports

javascript

// CommonJS style
const path = require('path');

console.log(__filename);  // Works in CommonJS
console.log(__dirname);

Only choose this if you have a specific reason to avoid ES modules.

How to fix ReferenceError: __filename is not defined in ES module scope in Node.js

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How to fix "ReferenceError: __filename is not defined in ES module scope"

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