WireMock is a simulator for HTTP-based APIs. Some might consider it a service virtualization tool or a mock server. It enables you to stay productive when an API you depend on doesn't exist or isn't complete. It supports testing of edge cases and failure modes that the real API won't reliably produce. And because it's fast it can reduce your build time from hours down to minutes. MockLab is a hosted API simulator built on WireMock, with an intuitive web UI, team collaboration and nothing to install. The 100% compatible API supports drop-in replacement of the WireMock server with a single line of code. Run WireMock from within your Java application, JUnit test, Servlet container or as a standalone process. Match request URLs, methods, headers cookies and bodies using a wide variety of strategies. First class support for JSON and XML. Get up and running quickly by capturing traffic to and from an existing API.