Prism vs Apidog

Free and open source

From $9 per user/month (indicative)

Free and open source. You pay in engineering time and CI minutes.

Priced noticeably below Postman for comparable team functionality.

Everything, self-hosted

Free plan for small teams with core design, mock and test features.

Established

Stoplight (SmartBear) · since 2017

Established

Apidog · since 2022

• The mock is generated from the spec, so it cannot silently diverge from the contract.
• Validation proxy mode checks that a real implementation matches its own spec.
• Zero configuration beyond having an OpenAPI file.

• Schema-driven mocks and assertions stay correct as the API definition changes.
• Meaningfully cheaper than Postman for equivalent team features.
• One tool instead of three for design, mocking and documentation.

• Useless without an accurate OpenAPI document.
• Limited stateful behaviour — it is spec-driven, not scenario-driven.
• Generated example data is uninteresting unless examples are in the spec.

• Younger vendor with a smaller community and fewer third-party integrations.
• Data residency and cloud storage need checking for regulated environments.
• Documentation quality is uneven in places.

Design-first API teams who want mocks that are provably in sync with the contract.

Teams doing design-first API development who want mocks and docs generated from the spec.