Mocky.io is a web-based service that allows developers to effortlessly create and manage mock APIs. Through its user-friendly interface available at https://designer.mocky.io/, users can design custom HTTP responses, which are especially useful for testing and prototyping applications without the need for a live backend. Mocky.io supports both JSON and XML response formats, and you can specify various HTTP status codes. This tool is ideal for developers who need to simulate API endpoints quickly and efficiently during the development process.