Skip to content
JS
Package

eventsource

WhatWG/W3C compliant EventSource client for Node.js and browsers

v5.1.2, 21 Sept 2026MITESM onlyTypes: BundledWebSockets and realtime
$ npm install eventsource

Key numbers

As of 25 Sept 2026
Weekly downloads
44.7m
+297% over 12 months
Gzip bundle size
-
No Bundlephobia data
Dependencies
1
Direct, from package.json
Last release
3 days ago
v5.1.2
GitHub stars
1.2k
266 forks
Open issues / PRs
1 / 0
Contributors
58
Commits, last 52 weeks
52

Downloads

Last week 2026-09-15 to 2026-09-21
020m40m60mSept 2025Mar 2026Sept 2026High 56.5m (25 Aug 2026)Low 7.9m (23 Dec 2025)
Weekly npm downloads, one point per week, weeks starting 23 Sept 2025 to 15 Sept 2026. The y axis starts at zero.

44,668,168 downloads last week, 199,184,110 in the last month. The 12-month change of +297% compares the average of the last 4 weeks with the first 4 weeks of the series.

Releases, last 12 months
650 in total
Latest version
5.1.2, 21 Sept 20263 days ago
First published
8 Feb 2012
Last push to GitHub
21 Sept 20263 days before the snapshot
Repository archived
No
Open issues
1
Open pull requests
0
Commits, last 52 weeks
52
Dependents on npm
1,623

Major versions

  1. v5 first release 5.0.0, 10 Aug 2026
  2. v4 first release 4.0.0, 13 May 2025
  3. v3 first release 3.0.0, 7 Dec 2024
  4. v2 first release 2.0.0, 2 Mar 2022
  5. v1 first release 1.0.0, 17 Apr 2017
  6. v0 first release 0.0.1, 8 Feb 2012

Recent releases

VersionPublished
5.1.221 Sept 2026
5.1.120 Aug 2026
5.1.014 Aug 2026
5.0.010 Aug 2026
4.1.14 Aug 2026
4.1.019 Nov 2025
4.0.013 May 2025
3.0.79 May 2025
3.0.627 Mar 2025
3.0.528 Jan 2025
3.0.428 Jan 2025
3.0.327 Jan 2025
3.0.213 Dec 2024
3.0.17 Dec 2024
Module format
ESM onlyFrom package.json type, main and exports fields
TypeScript types
Bundled
Node.js engine range
>=22.12.0
Runtimes
-
Unpacked size (npm)
100 kB
Dependencies (1)
eventsource-parser
npm install eventsource

CDN

jsDelivr: 839.6k requests in 30 days
  • jsDelivrhttps://cdn.jsdelivr.net/npm/eventsource@5.1.2/
  • unpkghttps://unpkg.com/eventsource@5.1.2/
  • esm.shhttps://esm.sh/eventsource@5.1.2
Sources: npm registry, npm downloads API, GitHub API, jsDelivr. Data fetched 25 Sept 2026.

Indexability: Indexed.