webtorrent

WebTorrent is a streaming torrent client that runs directly in a web browser or in a Node.js server environment — the same code works in both places without any plugins or browser extensions. Torrenting is a peer-to-peer (P2P) file sharing protocol where files are downloaded in small pieces from many different computers simultaneously, rather than from a single central server. Normally this requires a desktop application, but WebTorrent brings that capability to the web.

In browsers, WebTorrent uses WebRTC data channels — a technology already built into modern browsers for real-time communication — to connect directly with other users. Because it uses open web standards, it works across different websites: a WebTorrent client on one site can exchange data with a client on any other site. You can add a torrent using a magnet link (a short text identifier for a torrent), and the library will start fetching file pieces from peers as needed, allowing video and audio to begin playing before the full file is downloaded.

Developers would use this when building a web application that needs decentralized file sharing — for example, a video platform that does not want to pay for all the bandwidth, or a tool that lets users share files directly from their browsers without uploading to a central server. It is written in JavaScript and works in Node.js as well as in Chrome, Firefox, Opera, and Safari.