canirequire

canirequire › Dual (CommonJS + ESM) › ws

Is ws ESM-only? Can you require() it?

Simple to use, blazing fast and thoroughly tested websocket client and server for Node.js

Last verified Sep 9, 2026 against ws@8.21.3. JSON

Dual (CommonJS + ESM) Dual package — both require() and import work

ws publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.0). require("ws") and import "ws" both work on every supported Node.js version and in Bun.

Latest
8.21.3 (Aug 7, 2026)
Module format
Dual (CommonJS + ESM)
Last CommonJS version
8.21.3
Native ESM since
8.0.0
TypeScript types
@types/ws
Node engines
>=10.0.0
Weekly downloads
238.4M
License
MIT

Does ws@8.21.3 actually load? Runtime test results

Installed and executed on Sep 9, 2026 with require("ws") from a CommonJS file and import "ws" from an ES module.

Runtimerequire("ws")import "ws"
Node.js 18✓ works✓ works
Node.js 20✓ works✓ works
Node.js 22✓ works✓ works
Node.js 24✓ works✓ works
Node.js 26✓ works✓ works
Bun 1.4✓ works✓ works

How to import ws

ES modules (import)

import ws from "ws";

CommonJS (require)

const ws = require("ws");

Module format by version

Derived from the type, main and exports fields of every stable release on npm (181 versions; the newest 60 shown).

VersionsFormatFirst published
8.0.0 – 8.21.3Dual (CommonJS + ESM)Jul 28, 2021
7.4.1 – 7.5.13CommonJSDec 4, 2020

Frequently asked

Is ws ESM-only?

ws@8.21.3 ships CommonJS and ESM builds. ws publishes both a CommonJS entry and a native ESM entry (ESM added in 8.0.0). require("ws") and import "ws" both work on every supported Node.js version and in Bun.

Can I require ws?

Yes. ws ships a CommonJS entry, so require("ws") works on every Node.js version, alongside the native ESM entry for import.

Does ws work in Bun?

Yes. import "ws" loaded successfully in Bun 1.4 on Sep 9, 2026.

Does ws ship TypeScript types?

Not bundled. Install the community types with "npm install -D @types/ws".

Links

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