Insomnia

Insomnia is an open-source desktop API client and testing tool created by Gregory Schier in 2014, acquired by Kong Inc. in 2019, providing a cross-platform application for designing, debugging, testing, and documenting HTTP and GraphQL APIs with an intuitive visual interface, supporting REST, GraphQL, gRPC, WebSockets, Server-Sent Events, and SOAP protocols, used by over one million developers worldwide as a popular alternative to Postman. The request builder provides comprehensive HTTP request configuration including all methods, custom headers, query parameters with encoding options, request body formats supporting JSON, XML, form data, URL-encoded, binary, and GraphQL, authentication schemes including basic auth, bearer tokens, OAuth one and two, API keys, AWS IAM, and NTLM, and certificate management for mTLS connections, with environment variables for managing multiple deployment targets. The GraphQL support includes full schema introspection with automatic query, mutation, and subscription discovery, intelligent autocomplete for fields and arguments, request variables with type checking, fragment management, and subscription support through WebSocket transport, enabling comprehensive GraphQL API development and testing workflows. The response viewer displays formatted JSON with syntax highlighting, XML tree view, HTML preview, image rendering, raw byte view, header inspection, cookie management, and response time and size metrics, with the ability to extract values from responses using JSONPath, XPath, or regex for chaining in subsequent requests. The design documents enable API-first development through OpenAPI specification editing with live preview, code generation, and mock server. The Git sync enables team collaboration through version control. The plugin system extends functionality. Designed for API developers, backend engineers, and QA testers.