Package

engine.io-client

Client for the realtime Engine

v6.6.6, 16 Jun 2026MITESM + CommonJSTypes: BundledWebSockets and realtime

$ npm install engine.io-client

npm GitHub Homepage

Key numbers

As of 25 Sept 2026

Weekly downloads: 12.6m; +119% over 12 months
Gzip bundle size: -; No Bundlephobia data
Dependencies: 5; Direct, from package.json
Last release: 3 months ago; v6.6.6
GitHub stars: 63.2k; 10.3k forks
Open issues / PRs: 164 / 27
Contributors: -
Commits, last 52 weeks: 147

Downloads

Last week 2026-09-15 to 2026-09-21

Weekly npm downloads, one point per week, weeks starting 23 Sept 2025 to 15 Sept 2026. The y axis starts at zero.

12,575,868 downloads last week, 61,354,896 in the last month. The 12-month change of +119% compares the average of the last 4 weeks with the first 4 weeks of the series.

Maintenance

Releases, last 12 months: 5163 in total
Latest version: 6.6.6, 16 Jun 20263 months ago
First published: 3 Jul 2012
Last push to GitHub: 24 Sept 2026same day as the snapshot
Repository archived: No
Open issues: 164
Open pull requests: 27
Commits, last 52 weeks: 147
Dependents on npm: 191

Major versions

v6 first release 6.0.0, 8 Oct 2021
v5 first release 5.0.0, 10 Mar 2021
v4 first release 4.0.0, 10 Sept 2020
v3 first release 3.0.0, 5 Apr 2017
v2 first release 2.0.0, 22 Jan 2017
v1 first release 1.0.0, 6 Mar 2014
v0 first release 0.1.0, 3 Jul 2012

Recent releases

Version	Published
6.6.6	16 Jun 2026
6.6.5	20 May 2026
6.6.4	23 Dec 2025
3.5.6	19 Dec 2025
3.5.5	17 Nov 2025
6.6.3	23 Jan 2025
6.6.2	23 Oct 2024
6.6.1	21 Sept 2024
6.6.0	21 Jun 2024
3.5.4	18 Jun 2024
6.5.4	18 Jun 2024
6.5.3	9 Nov 2023
6.5.2	1 Aug 2023
6.5.1	28 Jun 2023

Compatibility

Module format: ESM + CommonJSFrom package.json type, main and exports fields
TypeScript types: Bundled
Node.js engine range: Not declared
Runtimes: -
Unpacked size (npm): 851 kB
Dependencies (5): wsdebugengine.io-parserxmlhttprequest-ssl@socket.io/component-emitter

Install

npm install engine.io-client

CDN

jsDelivr: 2.3m requests in 30 days

jsDelivrhttps://cdn.jsdelivr.net/npm/engine.io-client@6.6.6/
unpkghttps://unpkg.com/engine.io-client@6.6.6/
esm.shhttps://esm.sh/engine.io-client@6.6.6

Alternatives

Package	Weekly downloads	Gzip	Last release	Module	Comparison
sockjs SockJS-node is a server counterpart of SockJS-client a JavaScript library that provides a WebSocket-like object in the browser. SockJS gives you a coherent, cross-browser, Javascript API which creates a low latency, full duplex, cross-domain communication	13.9m	-	4 years ago	CommonJS	-

Sources: npm registry, npm downloads API, GitHub API, jsDelivr. Data fetched 25 Sept 2026.

Indexability: Indexed.