index.mdx

---
title: Run JavaScript Everywhere
layout: home
---

<section>
  <WithBadge section="index" />

  <div>
    <h1 className="special">Run JavaScript Everywhere</h1>

    Node.js® is a free, open-source, cross-platform JavaScript runtime environment
    that lets developers create servers, web apps, command line tools and scripts.

  </div>

  <div>
    <WithNodeRelease status={['LTS']}>
      {({ release }) => (
        <>
          <DownloadButton release={release}>Download Node.js (LTS)</DownloadButton>
          <small>
            Downloads Node.js <b>{release.versionWithPrefix}</b>
            <sup title="Downloads a Node.js installer for your current platform">1</sup> with long-term support.
            Node.js can also be installed via <Link href="/download">version managers</Link>.
          </small>
        </>
      )}
    </WithNodeRelease>

    <WithNodeRelease status={['Current']}>
      {({ release }) => (
        <small>
          Want new features sooner?
          Get <b>Node.js <DownloadLink release={release}>{release.versionWithPrefix}</DownloadLink></b>
          <sup title="Downloads a Node.js installer for your current platform">1</sup> instead.
        </small>
      )}
    </WithNodeRelease>

  </div>
</section>

<section>
  <div>
    ```js displayName="Create an HTTP Server"
    // server.mjs
    import { createServer } from 'node:http';

    const server = createServer((req, res) => {
      res.writeHead(200, { 'Content-Type': 'text/plain' });
      res.end('Hello World!\n');
    });

    // starts a simple http server locally on port 3000
    server.listen(3000, '127.0.0.1', () => {
      console.log('Listening on 127.0.0.1:3000');
    });

    // run with `node server.mjs`
    ```

    ```js displayName="Write Tests"
    // tests.mjs
    import assert from 'node:assert';
    import test from 'node:test';

    test('that 1 is equal 1', () => {
      assert.strictEqual(1, 1);
    });

    test('that throws as 1 is not equal 2', () => {
      // throws an exception because 1 != 2
      assert.strictEqual(1, 2);
    });

    // run with `node tests.mjs`
    ```

    ```js displayName="Read and Hash a File"
    // crypto.mjs
    import { createHash } from 'node:crypto';
    import { readFile } from 'node:fs/promises';

    const hasher = createHash('sha1');

    hasher.setEncoding('hex');
    // ensure you have a `package.json` file for this test!
    hasher.write(await readFile('package.json'));
    hasher.end();

    const fileHash = hasher.read();

    // run with `node crypto.mjs`
    ```

    ```js displayName="Streams Pipeline"
    // streams.mjs
    import { pipeline } from 'node:stream/promises';
    import { createReadStream, createWriteStream } from 'node:fs';
    import { createGzip } from 'node:zlib';

    // ensure you have a `package.json` file for this test!
    await pipeline
    (
      createReadStream('package.json'),
      createGzip(),
      createWriteStream('package.json.gz')
    );

    // run with `node streams.mjs`
    ```

    ```js displayName="Work with Threads"
    // threads.mjs
    import { Worker, isMainThread,
      workerData, parentPort } from 'node:worker_threads';

    if (isMainThread) {
      const data = 'some data';
      const worker = new Worker(import.meta.filename, { workerData: data });
      worker.on('message', msg => console.log('Reply from Thread:', msg));
    } else {
      const source = workerData;
      parentPort.postMessage(btoa(source.toUpperCase()));
    }

    // run with `node threads.mjs`
    ```

  </div>
  Learn more what Node.js is able to offer with our [Learning materials](/learn).
</section>