Hoppscotch is a fast, lightweight, open-source alternative to Postman. It runs in the browser with no installation required.
Hoppscotch provides a fast, browser-based API testing experience as an open-source alternative to Postman. It supports REST, GraphQL, WebSocket, SSE, and Socket.IO protocols with a clean, keyboard-friendly interface. Being a web application means there is nothing to install — just open the URL and start testing. Hoppscotch also offers a CLI for CI integration and a self-hosted option for teams that need to keep API testing within their infrastructure. Its lightweight approach and open-source license make it popular among developers who want Postman-like functionality without the bloat or vendor lock-in.