Insomnia vs Specmatic

From $12 per user/month (indicative)

Free tier available

Free for solo use; paid tiers add collaboration, cloud sync and enterprise controls.

Open source core; commercial support and an enterprise insights product are sold separately.

Free plan for individuals with local storage.

Open-source core covering contract testing and stubbing.

Widely used

Kong · since 2016

Emerging

Specmatic · since 2020

• Noticeably faster and lighter than Postman for everyday request work.
• Best-in-class GraphQL and gRPC ergonomics.
• Design-first OpenAPI workflow with linting built in.

• Spec-driven rather than consumer-driven, so it needs far less cross-team process than Pact.
• The same spec produces both the provider test and the consumer mock.
• Covers async messaging (Kafka, AsyncAPI) as well as HTTP.

• A forced-account change in 2023 damaged trust; check the current model before standardising on it.
• Test scripting is less capable than Postman's.
• Smaller ecosystem of shared collections.

• Only works if your specs are accurate and maintained.
• Smaller community than Pact, with fewer worked examples.
• Primarily JVM-oriented tooling.

Developers who mainly want a fast client with excellent GraphQL support.

Spec-first organisations that want contract enforcement without the Pact process overhead.