# Socket.IO

Bidirectional and low-latency communication for every platform

Repository: https://github.com/socketio/socket.io
Canonical: https://ross.abutalabs.com/products/socketio
Homepage: https://socket.io
Language: TypeScript
License: MIT
License Family: permissive
Topics: javascript, nodejs, socket-io, websocket
Last push: 2026-07-24T14:44:59+00:00

## Health v2 (maintenance only)
Score: 95/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 93, longevity 100
- inputs: {"age_days": 6019, "days_push": 40, "days_rel": 48, "gap_med": 0.0, "n_releases_24m": 35}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 63207, forks 10302 (observed 2026-08-28T04:12:19.155235+00:00)

## What it is
Socket.IO is a library enabling bidirectional, low-latency, event-based communication between servers and clients over WebSockets with automatic fallbacks. It includes server and client implementations (JavaScript, Java, and more) plus adapters for scaling across multiple nodes.

## Use cases
- build a real-time chat application
- push live notifications to browsers
- stream live updates to a dashboard
- implement multiplayer game communication
- add realtime collaboration to a web app
- scale websocket connections across multiple servers

## When to choose
- you need reliable bidirectional realtime messaging with automatic reconnection and fallbacks
- you want rooms, namespaces, and broadcasting out of the box
- you need clients across platforms (browser, Node.js, Java, etc.)

## When to avoid
- you only need plain WebSocket with no extra features and want minimal overhead
- you need strict standards compliance rather than Socket.IO's custom protocol
- you are building a simple request/response API better served by HTTP or REST

## Facets
- artifact type: library
- maturity: stable
- function: websocket, http-server, middleware, rpc
- domain: web-development, backend
- platform: cross-platform
- tags: realtime, bidirectional-communication, long-polling-fallback, rooms-and-namespaces, horizontal-scaling, typescript, real-time, messaging, nodejs, javascript, web-server

## Member repositories
- socketio/socket.io (main) score 95
- socketio/socket.io-client (mirror) score 23
- socketio/socket.io-client-java (sdk) score 39
- socketio/engine.io (backend) score 23
- socketio/socket.io-redis-adapter (plugin) score 62

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:12:19.155235+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T16:17:27.014919+00:00, confidence not recorded.
  - readme: https://github.com/socketio/socket.io (fetched 2026-08-28T04:12:19.155235+00:00, sha 17b791d075c5)
- Data as of 2026-08-30T08:39:29.467469+00:00.