Hoppscotch is an API client that opens in a browser tab and is ready in under a second. It began as a deliberately minimal alternative to the heavyweight desktop clients, and that restraint is still the point: no installer, no launch time, no account required to send a request.
Coverage goes beyond plain REST. It handles GraphQL with schema introspection and query building, WebSocket connections, Socket.IO, server-sent events and MQTT, all in the same interface. For anyone debugging a realtime feature, having the websocket client in the same place as the REST client removes a tool switch. Authentication helpers cover basic, bearer, OAuth 2.0, API keys and AWS signature, so the awkward parts are handled without hand-rolling headers.
Collections organise saved requests, environments hold variables for switching between local, staging and production, and pre-request scripts and tests are written in JavaScript in the familiar style. Collections can be run as a suite, and the command line runner executes them in CI, which makes an API contract test out of the same definition your team already uses interactively.
The characteristic that sets it apart is deployment flexibility. Hoppscotch is open source under the MIT licence and can be self-hosted with Docker, so an organisation that will not send request bodies containing customer data to a third-party cloud can run the whole thing internally. There is also a browser extension that bypasses CORS restrictions when testing APIs that have not been configured for browser access, which is the one genuine friction point of a browser-based client.
What you give up against the established incumbents is ecosystem. There are fewer integrations, a smaller plugin library, less third-party tooling built around it, and a smaller body of tutorials when something behaves unexpectedly. Team collaboration features exist but are younger. For a large organisation standardising across hundreds of engineers, that maturity gap is a real consideration; for a team of six, it rarely comes up.
Who it suits: developers who want a fast client without an installer, and teams who need to self-host their API tooling. Who should look elsewhere: large organisations needing mature governance, audit and integration ecosystems.