WebTorrent vs BitTorrent
Traditional torrent clients use UDP and TCP to talk to a swarm of peers. Browsers cannot make raw UDP or TCP connections due to security constraints. WebTorrent bridges this gap. It replaces raw sockets with WebRTC (the same technology powering Google Meet and Zoom), which allows browsers to establish direct P2P connections with other browsers in the swarm securely.
Sequential Downloading
For streaming to work, the client has to change its download priority. Usually, torrent software requests the rarest pieces of a file first to optimize swarm health. When streaming, the algorithm is flipped to 'sequential' mode. The client prioritizes piece 1, then piece 2, then piece 3, ensuring that the video buffer fills up directly ahead of the playhead.
Converting a Magnet Link to a Stream
When you paste a Magnet link into a WebTorrent-compatible player, the client fetches the metadata. It parses the video container (like MP4 or WebM) and connects it virtually to an HTML5 <video> element. The video element thinks it is playing a standard HTTP stream, while under the hood, the client intercepts the byte requests and fetches them from peer nodes in real-time.