The interface org.springframework.web.reactive.function.client.WebClient is a reactive web client introduced in Spring 5 that can be used to perform web requests. Similarly there is org.springframework.test.web.reactive.server.WebTestClient interface, which is a special WebClient—used to write unit tests within your application. WebClient is the reactive version of RestTemplate, which works over the HTTP/1.1 protocol. They are packaged as part of the spring-webflux module.