Prism vs WireMock

Free and open source

Free tier available

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

Open source is free; WireMock Cloud is a paid hosted service for shared team mocks.

Everything, self-hosted

Open-source WireMock is complete and free.

Established

Stoplight (SmartBear) · since 2017

Category standard

WireMock Inc. · since 2013

• 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.

• Fault and latency injection lets you test the error paths that never occur on demand in a real sandbox.
• Record-and-replay produces a realistic mock from live traffic quickly.
• Runs anywhere: embedded, standalone, container or cloud.

• 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.

• Recorded stubs drift from the real service unless you re-record or verify contracts.
• Complex stateful scenarios get verbose in JSON.
• HTTP only — not for message queues or gRPC without extensions.

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

Teams whose integration tests depend on third-party HTTP services.