Mockoon vs Prism

From $100 per month (Team, billed annually, up to 5 members)

Free and open source

Free locally and forever; the paid cloud tier adds hosted mocks and team sync. Team covers 5 members, 3 cloud-deployed mocks and 100k calls a month, with Enterprise on a quote. Work emails get a 14-day trial, others 7 days with a card.

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

The desktop app and CLI are free and open source.

Everything, self-hosted

Widely used

Mockoon · since 2017

Established

Stoplight (SmartBear) · since 2017

• Genuinely a minute from download to a working mock API.
• Dynamic templating with faker-style helpers produces realistic responses.
• Proxy mode mocks only the routes you need and passes the rest through.

• 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.

• Desktop-first; sharing mocks across a team needs the paid cloud or a committed config file.
• HTTP only.
• Less suited to complex stateful behaviour than WireMock.

• 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.

Front-end developers unblocking themselves while a backend is still being built.

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