Insomnia
The open-source, collaborative API development platform
About Insomnia
Insomnia is an open-source, cross-platform API client by Kong for designing, debugging, and testing REST, GraphQL, gRPC, WebSocket, SSE, and SOAP APIs. It features native OpenAPI editing, AI-powered mock server generation, MCP client support, and flexible storage options including local, Git, and cloud sync.
Pros & Cons
Pros
- Clean, intuitive UI that's easy to navigate without feeling cluttered
- Excellent GraphQL support with automatic schema introspection and intelligent autocomplete
- Open-source core under MIT license with all essential features free
- Lightweight and fast — launches quickly and uses less memory than alternatives
- Flexible storage options: local, Git, or cloud sync with end-to-end encryption
- Strong plugin ecosystem with 350+ community extensions
Cons
- Smaller integration ecosystem compared to Postman
- Limited built-in API documentation publishing capabilities
- Team collaboration features less mature than competitors
- Free tier limited to 3 users for Git Sync projects
- No built-in scheduled API monitoring
Key Features
Multi-Protocol API Client
Send HTTP, REST, gRPC, GraphQL, WebSocket, SOAP, and SSE requests from a single unified interface
OpenAPI Design & Validation
Native OpenAPI editor with real-time linting, visual preview, and spec validation for API-first development
API Mocking
Generate instant mock servers with AI-powered responses, available locally or in the cloud
Git Sync
Sync API collections and design specs with Git repositories for version control and team collaboration
MCP Client Support
Test and debug Model Context Protocol (MCP) servers directly within Insomnia
Automated Testing
Native test suites and collection runner for automated API validation with Inso CLI for CI/CD pipelines
Plugin Ecosystem
Open-source plugin architecture with 350+ community-built plugins for extensibility
End-to-End Encryption
Secure cloud sync with end-to-end encryption ensuring API data privacy
Environment Management
Unlimited environments for managing variables across development, staging, and production contexts
Pricing
- Unlimited Git Sync projects (up to 3 users)
- Unlimited Cloud/Local projects
- Inso CLI access
- Unlimited collection runs & environments
- 1,000 mock server requests/month
- End-to-end encryption
- Unlimited plugins
- Everything in Essentials
- Unlimited users with Git Sync
- Unlimited organizations
- Role-based access control (RBAC)
- 10,000 mock server requests/month
- Everything in Pro
- SSO (SAML/OIDC) and SCIM
- Storage mandate controls
- Domain capture and invite controls
- Enterprise support & SOC2 compliance
- Native vault integrations (AWS, GCP, Hashicorp, Azure)
- Unlimited mock server requests
Best For
API Development & Debugging
Quickly build, test, and debug REST, GraphQL, and gRPC APIs with an intuitive desktop client
API-First Design
Design APIs using the native OpenAPI editor with real-time validation before writing any code
CI/CD Pipeline Integration
Automate API testing in continuous integration pipelines using the Inso CLI tool
MCP Server Testing
Test and debug Model Context Protocol servers for AI agent integrations
Team API Collaboration
Share API collections and specs across development teams with Git-based version control
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Featured In
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Best for teams practicing API-first development. The combined OpenAPI editor and multi-protocol client provides a complete design-to-test workflow that no other open-source tool matches.
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Most feature-rich open-source option — strongest for teams that need API design + testing in one tool, but watch the paid/free boundary carefully.
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Best mature desktop GraphQL client for teams working across GraphQL and REST — strong feature set with a polished interface.
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Best for spec-first teams who want OpenAPI-driven contract tests and live in the Kong ecosystem.