Mockoon vs Mock Service Worker

From $9 per user/month (indicative, Cloud)

Free and open source

Free locally; the paid cloud tier adds hosted mocks and team sync.

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

Category standard

OSS community · since 2020

• 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.

• One set of handlers reused across unit, component, E2E and local development.
• Application code is completely unaware it is being mocked — no test-only branches.
• Supports REST and GraphQL with the same model.

• 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.

• JavaScript ecosystem only.
• Service Worker registration adds a setup step and occasional caching confusion.
• Handlers can drift from the real API without contract verification.

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

Front-end teams that want one mocking approach across every kind of test.