A wrapper around node worker_thread with easy promise based api.

Usage no npm install needed!

<script type="module">
  import shahidcodesThreadifier from 'https://cdn.skypack.dev/@shahidcodes/threadifier';




Node has recently added worker_thread, giving us ability to run long running synchronous tasks in a separate thread. But API is not very seamless.
Threadifier allows you to run any function in different thread seamlessly through its easy to use promise based api. It uses worker_threads module to run the given function in a new thread and return the response asynchronously so your event loop keeps running. Also you can create a worker thread pool to reuse the same threads for various tasks.

Get started

npm i @shahidcodes/threadifier


Run a function in different thread.

const Threadifier = require('@shahidcodes/threadifier');

function runTask(arg) {
  let i = 0;
  for (let index = 0; index < 99999999; index++) {
  return `worked- loop count ${i}, arg: ${JSON.stringify(arg)}`;

const args = { name: 'Shahid' };

Threadifier.run(runTask, args)

Create a pool of threads and queue the tasks (recommended)

const { WorkerPool } = require('@shahidcodes/threadifier');

const pool = new WorkerPool(10);

function runTask(args) {
  let i = 0;
  for (let index = 0; index < 999999999; index++) {
  return { i, args };

const args = { name: 'Shahid' };

for (let index = 0; index < 100; index++) {
    .queueTask(runTask, args)
    .then(result => console.log(`from worker:`, result))

General Advice

You should not create many threads at once. If you're going to use this in a request handler/controller then better use a fixed size thread pool. And queue tasks otherwise you'll see CPU spikes when you spawn many many threads than the server can handle. One other reason you should use a thread pool is creating worker thread is expensive so if you're creating threads again n again then better use pool.


Please check the examples directory.


You're free to submit PRs. There are no build/tests yet. But it is in roadmap.


Feel free to contact me on twitter.com/shahidcodes