Catalog comparison
InsomniaREST Assured
Side-by-side facts from the TestGuild Tool Matcher catalog. Empty cells mean the catalog does not list that attribute — not that the product lacks it.
Beautiful API collaboration platform for debugging, designing, testing, and mocking APIs. Supports REST, GraphQL, gRPC, WebSocket, and SSE with local, Git, and cloud storage options.
Java library that brings the simplicity of testing REST services from dynamic languages like Ruby and Groovy into the Java domain. Makes testing and validating REST services in Java much easier with fluent API syntax.
At a glance
Primary testing surface
Insomnia
Api
REST Assured
Api
Primary capability
Insomnia
Automation
REST Assured
Automation
License and pricing
Insomnia
freemium · open source
REST Assured
free · open source
Free trial
Insomnia
No
REST Assured
No
Free-tier limit
Insomnia
Essentials plan with unlimited collections, Git Sync for up to 3 users, and unlimited cloud/local projects
REST Assured
Not listed in catalog
Complexity
Insomnia
beginner
REST Assured
beginner
Team fit
Insomnia
enterprise, large, medium, small
REST Assured
enterprise, large, medium, small
Test authoring languages
Insomnia
JavaScript, JSON
REST Assured
Groovy, Java, Kotlin, Scala
Supported platforms
Insomnia
GraphQL, gRPC, macOS, REST APIs, Server-Sent Events (SSE), Ubuntu/Linux, WebSocket, Windows
REST Assured
Any Java-supported OS, HTTP/REST APIs, JSON APIs, SOAP Services, XML APIs
MCP server
Insomnia
No
REST Assured
No
Key features (catalog)
Insomnia
API client for REST, GraphQL, gRPC, WebSocket, API contract testing, API design and documentation, API documentation generation, API mocking capabilities, API testing and debugging, Authentication support, Beautiful graphical user interface, Built-in conflict resolution, Cloud storage and collaboration +25 more
REST Assured
API contract testing, Authentication support (Basic, OAuth, etc.), Cookie handling and validation, CSRF token support, Custom serialization/deserialization, Detailed error reporting, File upload testing, Fluent API syntax, Form parameter support, Functional testing +26 more
Limitations (catalog)
Insomnia
Cloud features require Kong account, Enterprise features need subscription, Limited compared to some specialized tools, Recent changes may have affected user experience, Some advanced features require paid plans
REST Assured
Java ecosystem only, JVM platform required, Learning curve for Groovy syntax, No GUI interface, Requires Java knowledge
| Attribute | Insomnia | REST Assured |
|---|---|---|
| Primary testing surface | Api | Api |
| Primary capability | Automation | Automation |
| License and pricing | freemium · open source | free · open source |
| Free trial | No | No |
| Free-tier limit | Essentials plan with unlimited collections, Git Sync for up to 3 users, and unlimited cloud/local projects | Not listed in catalog |
| Complexity | beginner | beginner |
| Team fit | enterprise, large, medium, small | enterprise, large, medium, small |
| Test authoring languages | JavaScript, JSON | Groovy, Java, Kotlin, Scala |
| Supported platforms | GraphQL, gRPC, macOS, REST APIs, Server-Sent Events (SSE), Ubuntu/Linux, WebSocket, Windows | Any Java-supported OS, HTTP/REST APIs, JSON APIs, SOAP Services, XML APIs |
| MCP server | No | No |
| Key features (catalog) | API client for REST, GraphQL, gRPC, WebSocket, API contract testing, API design and documentation, API documentation generation, API mocking capabilities, API testing and debugging, Authentication support, Beautiful graphical user interface, Built-in conflict resolution, Cloud storage and collaboration +25 more | API contract testing, Authentication support (Basic, OAuth, etc.), Cookie handling and validation, CSRF token support, Custom serialization/deserialization, Detailed error reporting, File upload testing, Fluent API syntax, Form parameter support, Functional testing +26 more |
| Limitations (catalog) | Cloud features require Kong account, Enterprise features need subscription, Limited compared to some specialized tools, Recent changes may have affected user experience, Some advanced features require paid plans | Java ecosystem only, JVM platform required, Learning curve for Groovy syntax, No GUI interface, Requires Java knowledge |
How the trade-offs apply to your team
Guidance below is inferred only from catalog differences. It is not a winner pick.
Consider Insomnia if…
- you need coverage for GraphQL, gRPC, macOS, REST APIs
- your team writes tests in JavaScript, JSON
- you care about API client for REST, GraphQL, gRPC, WebSocket and API design and documentation
Consider REST Assured if…
- you need coverage for Any Java-supported OS, HTTP/REST APIs, JSON APIs, SOAP Services
- your team writes tests in Groovy, Java, Kotlin, Scala
- you care about Authentication support (Basic, OAuth, etc.) and Cookie handling and validation
Questions to verify before choosing
- Confirm current pricing and packaging on the Insomnia and REST Assured websites.
- Trial both tools against a real slice of your application, not a demo site.
- Verify the exact browser, device, or OS matrix you must support.