Rex is a robust and fast REST API client designed for developers who need to test APIs directly within their Chrome browser. This free add-on allows users to send HTTP requests, work with various body types, and authenticate in multiple ways, all while ensuring that their data remains local. The tool supports GET, POST, PUT, PATCH, DELETE, and more, with a visual editor for easy configuration of parameters and headers.

In addition to its core features, Rex offers advanced capabilities such as request chaining, pre-request scripts, and a dedicated GraphQL mode with real-time autocomplete. Users can save requests into organized collections, manage environments, and view their request history with side-by-side comparison of responses. With a focus on privacy and data security, Rex stores everything locally, ensuring a seamless and efficient workflow without the need for accounts or cloud storage.