无状态服务器是指一种把每个请求作为与之前任何请求都无关的独立的事务的服务器。

无状态的设计简化了服务器端的设计，不必动态分配存储空间以处理进行中的会话。如果客户端在事务处理中间被中断了，系统不必为清理服务器状态而作出响应。

缺陷是有时候在每个请求时包括附加的信息是必要的，这些额外信息需要服务器来解释。

In computing, a stateless protocol is a communications protocol that treats each request as an independent transaction that is unrelated to any previous request so that the communication consists of independent pairs of request and response. A stateless protocol does not require the server to retain session information or status about each communications partner for the duration of multiple requests. In contrast, a protocol which requires keeping of the internal state on the server is known as a stateful protocol.