Insomnia
Open-source, cross-platform API client for GraphQL, REST, WebSockets, SSE & gRPC with flexible storage options.
Insomnia is a free, open-source API client that supports multiple protocols (GraphQL, REST, WebSockets, SSE, gRPC) and offers three storage backends: local, Git, and cloud (E2EE). It is a lighter and more privacy-respecting alternative to Postman.