Hoppscotch

Hoppscotch is an open-source API development and testing platform created by Liyas Thomas in 2019, providing a lightweight web-based alternative to Postman for building, testing, documenting, and sharing API requests, with support for REST, GraphQL, WebSocket, Server-Sent Events, and Socket.io protocols, running entirely in the browser without requiring installation or account creation for basic functionality. The request builder supports all HTTP methods with configurable headers, query parameters, request body formats including JSON, form data, URL-encoded, and binary, authentication schemes including bearer tokens, basic auth, API keys, OAuth two point zero, and AWS signature version four, and environment variables for managing different deployment targets. The collections and folders organize requests into logical groups with shared authentication and headers, while the test runner executes collections sequentially with pre-request scripts for dynamic data generation and test assertions for response validation, enabling automated API testing workflows. The GraphQL introspection automatically discovers available queries, mutations, and subscriptions from the schema, with auto-complete suggestions as you type. The WebSocket and SSE support enables testing real-time communication endpoints. The response viewer displays formatted JSON, XML, HTML, and raw responses with syntax highlighting, header inspection, response time and size metrics, and status code validation. The environments and variables enable context switching between development, staging, and production configurations. The team collaboration through workspaces enables sharing collections with team members. The self-hosted option provides complete data control. Designed for API developers, backend engineers, QA testers, and integration teams.