Insomnia vs RESTK

Insomnia is an API collaboration platform for designing, testing, debugging, mocking, and governing APIs. Its client supports HTTP, REST, gRPC, GraphQL, WebSockets, SOAP, and SSE. Design workflows include OpenAPI spec-first work, live previews, and generation of collections, tests, and mocks. Mocks can be generated from collections, OpenAPI specifications, API responses, or natural-language descriptions, locally or in the cloud. The collection runner supports unlimited runs, JavaScript before-request and after-response scripts, chained requests, and CI/CD execution through Inso CLI. Insomnia also connects to HTTP and STDIO MCP servers, supports custom tool parameters, and provides MCP authentication event logs. API data can stay local, reside in a Git repository, or be stored in Insomnia Cloud with optional end-to-end encryption. Teams can share projects, collections, mocks, and design specifications with organization controls and real-time collaboration indicators. Essentials is free; Pro is $12 a month per user, and Enterprise is $45 a month per user. It supports Linux, macOS, Windows, and self-hosted use.

RESTK has no write-up on Specifiction yet; its figures are above.