API Spector vs Insomnia
Short version: Insomnia is a well-designed API client, now maintained by Kong, that has moved toward accounts and cloud sync. API Spector is local-first, adds contract testing and test-code export, and never requires an account.
What Insomnia is
Insomnia is a desktop API client known for a clean interface and support for REST, GraphQL, gRPC, and WebSockets, plus a design view for OpenAPI specs and a plugin ecosystem. Since Kong's stewardship it has leaned toward sign-in and cloud features, which prompted some users to look for offline-first alternatives.
Side by side
| API Spector | Insomnia | |
|---|---|---|
| Local-first / offline | Yes | Supported, but account and cloud are emphasised |
| Account required | No | Prompted; some features gated |
| Secret managers | Vault, AWS, Azure, GCP, 1Password (+ AES-256-GCM local) | Environment variables, plugins |
| GraphQL query builder | Yes, introspection-driven | Yes |
| SOAP + WSDL loader | Yes, load a WSDL and generate the envelope | No |
| Export to test code | Robot Framework, Playwright, Karate, REST Assured, supertest | Snippets; Inso CLI for its own runner |
| Contract testing | Built in, Pact-compatible | Not built in |
| OpenAPI test coverage | Yes, with a CI gate | No |
| Mock servers | Local and cloud | Cloud mocks |
| Protocols | HTTP/REST, GraphQL (+ subscriptions), SOAP/WSDL, WebSocket, Socket.IO, MQTT, SSE, gRPC (unary + server streaming) | HTTP/REST, GraphQL, gRPC, WebSocket |
| Visual flows | Yes, chain requests on a canvas | No |
| Fuzz testing | Yes, spec-driven, built in | No |
| Storage | Files (Git-friendly) | Local DB, with cloud/Git sync options |
Where API Spector fits
- Author faster. An introspection-driven GraphQL query builder, a SOAP WSDL loader that fills in the envelope, nested environments that inherit with
Extends, and Vault / AWS / Azure / GCP / 1Password secret references, all built in - no plugins. - More than a request client. Chain requests into visual flows, fuzz a request for crashes and missing validation, run setup and teardown with hooks, and version the workspace with a built-in Git client.
- No account, no nudging. The app is fully usable offline with nothing to sign in to.
- From request to test code. Export a collection to Robot Framework, Playwright, Karate, REST Assured, or supertest and run it in your stack.
- Contract testing included. Pact-compatible consumer/provider verification is part of the tool, not a separate product.
API Spector is a European alternative: built in Europe, GDPR-first, and local-first (your API data stays on your machine), with the optional cloud hosted in the EU.
Pricing
The desktop app is free; API Spector Cloud is Pro €12/user/mo or Team €19/user/mo with SSO included. Insomnia's SSO is Enterprise-only ($45/user/mo). See the cost for your team size.
Choose Insomnia if
- You need deeper gRPC (client/bidi streaming, reflection), or you are invested in its plugin ecosystem and OpenAPI design view.
- You are happy with its account and cloud-sync model.
Choose API Spector if
- You want a strictly local-first client with secrets that never leave your machine.
- You want contract testing and code export in the same tool.
- You prefer collections stored as files you can review in Git.