HTTPWebSocket

HTTPWebSocket is an informal term used to describe the WebSocket protocol as initiated over an HTTP connection. The WebSocket protocol provides a full-duplex, persistent communication channel between a client and server, and its connection begins with an HTTP/1.1 upgrade handshake. That handshake uses HTTP headers such as Upgrade: websocket and Connection: Upgrade together with Sec-WebSocket-Key and related fields defined in RFC 6455.

The handshake allows clients (typically web browsers) and servers to negotiate a protocol switch without starting a separate TCP session. Once upgraded, the transport departs from HTTP semantics and operates on a framed message format that supports text and binary data, multiplexing, and optional extensions like permessage-deflate. Secure WebSocket connections use TLS and are identified by the wss:// scheme; non-encrypted connections use ws://.

Common uses include real-time web applications such as chat, live data feeds, collaborative editing, and multiplayer games. WebSocket is often preferred over HTTP polling or long polling where low-latency bidirectional exchange is required.

Interoperability and deployment issues include proxy and firewall handling of Upgrade requests, origin and cross-site considerations, and the need to validate and sanitize incoming messages. Implementations exist across major browsers and server frameworks, and the protocol can be integrated with authentication mechanisms and subprotocol negotiation for application-level use.