# Socket.IO

> Socket.IO — Bidirectional and low-latency communication for every platform

**Category:** saas / unknown  
**Domain:** socket.io  
**Source:** [Toneeto](https://www.toneeto.com/discover/socket.io)  
**Last updated:** April 12, 2026

## Changelog

### Apr 12, 2026 — Update

No updates detected in 25 days. Previous cadence: every 4 days.

### Mar 18, 2026 — New Feature

Socket.IO v4.8.3 was released on March 18, 2026; Socket.IO v4.8.3 fixed issue where calling io.close() on a stopped server would 

- Socket.IO v4.8.3 was released on March 18, 2026 _(90% confidence)_
- Socket.IO v4.8.3 fixed issue where calling io.close() on a stopped server would throw _(90% confidence)_

### Mar 17, 2026 — New Feature

Socket.IO parser v4.2.6 was released on March 17, 2026; Socket.IO parser v4.2.6 added limit to number of binary attachments

- Socket.IO parser v4.2.6 was released on March 17, 2026 _(90% confidence)_
- Socket.IO parser v4.2.6 added limit to number of binary attachments _(90% confidence)_

### Mar 10, 2026 — New Feature

Engine.IO v6.6.6 was released on March 10, 2026; Engine.IO v6.6.6 added @types/ws as dependency

- Engine.IO v6.6.6 was released on March 10, 2026 _(90% confidence)_
- Engine.IO v6.6.6 added @types/ws as dependency _(90% confidence)_

### Sep 21, 2024 — New Feature

Socket.IO v4.8.0 was released on September 21, 2024; Socket.IO v4.8.0 added custom transport implementations feature; Socket.IO v4.8.0 added tryAllTransports option (+2 more)

- Socket.IO v4.8.0 was released on September 21, 2024 _(90% confidence)_
- Socket.IO v4.8.0 added custom transport implementations feature _(90% confidence)_
- Socket.IO v4.8.0 added tryAllTransports option _(90% confidence)_
- Socket.IO v4.8.0 fixed issue allowing to join a room in middleware for uws _(90% confidence)_
- Socket.IO v4.8.0 fixed async close on adapters _(90% confidence)_

### Jun 1, 2023 — New Feature

Socket.IO v4.7.0 added support for WebTransport

- Socket.IO v4.7.0 added support for WebTransport _(90% confidence)_

### Feb 1, 2023 — New Feature

Socket.IO v4.6.0 introduced Connection state recovery

- Socket.IO v4.6.0 introduced Connection state recovery _(90% confidence (cross-referenced))_

### Nov 1, 2021 — New Feature

Socket.IO v4.4.0 added support for uWebSockets.js

- Socket.IO v4.4.0 added support for uWebSockets.js _(90% confidence)_

### May 1, 2021 — New Feature

Socket.IO v4.1.0 introduced serverSideEmit() function

- Socket.IO v4.1.0 introduced serverSideEmit() function _(90% confidence)_

### Mar 1, 2021 — New Feature

Socket.IO v4 was released in March 2021

- Socket.IO v4 was released in March 2021 _(90% confidence)_

### Nov 1, 2020 — New Feature

Socket.IO v3 was released in November 2020

- Socket.IO v3 was released in November 2020 _(90% confidence)_

### May 1, 2017 — New Feature

Socket.IO v2 was released in May 2017

- Socket.IO v2 was released in May 2017 _(90% confidence)_

## Competitors

- [Node.js](https://www.toneeto.com/discover/nodejs.org)
- [Flask Python](https://www.toneeto.com/discover/flaskpython.com)
- [Bootstrap](https://www.toneeto.com/discover/getbootstrap.com)
- [Webpack](https://www.toneeto.com/discover/webpack.com.ar)
- [FreeSWITCH](https://www.toneeto.com/discover/signalwire.com)

## Audience Segments

### startup_team (50% fit)

**Use case:** Socket for small teams
**Why:** Insufficient evidence for specific segmentation, defaulting to startup_team
**Key considerations:** ease of use, value for money

## Gotchas & Limitations

- Connectivity issues [moderate]
- Complexity in larger groups [moderate]
- Performance overhead [moderate]

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*Data verified by [Toneeto](https://www.toneeto.com/discover/socket.io). JSON available at [/api/co/socket.io](https://www.toneeto.com/api/co/socket.io).*