@b9g/node-webworker

Minimal Web Worker shim for Node.js until native support arrives.

Why This Package Exists

Node.js lacks native Web Worker support, despite being a web standard since 2009. This package provides a minimal, reliable shim using Node.js worker_threads until native support is added.

Canonical Issue: https://github.com/nodejs/node/issues/43583 Please 👍 and comment on the issue to show demand for native Web Worker support!

Installation

npm install @b9g/node-webworker

Usage

import {Worker} from '@b9g/node-webworker';

// Create a worker (same API as Web Workers)
const worker = new Worker('./worker.js', { type: 'module' });

// Listen for messages
worker.addEventListener('message', (event) => {
  console.log('Received:', event.data);
});

// Send a message
worker.postMessage({ hello: 'world' });

// Terminate when done
worker.terminate();

Exports

Classes

• Worker - Web Worker implementation using Node.js worker_threads
• MessageEvent - Event class for worker messages
• ErrorEvent - Event class for worker errors

Default Export

• Worker - The Worker class

Features

• Standards-compliant API - Drop-in replacement for Web Workers
• ES Module support - Works with modern JavaScript
• Minimal overhead - Thin wrapper around worker_threads
• Error handling - Proper event forwarding
• Clean termination - Resource cleanup

Limitations

• Node.js only - Don't use this in browsers (they have native Web Workers)
• Module workers only - Classic workers with importScripts() not supported
• Serialization differences - Uses Node.js structured clone, not web's algorithm

Deprecation Notice

⚠️ This package will be deprecated once Node.js implements native Web Workers.

We maintain this as a temporary workaround. Please help push for native support by engaging with nodejs/node#43583.

License

MIT