Mock Service Worker vs Mockoon

Free and open source

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

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

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

Everything, self-hosted

The desktop app and CLI are free and open source.

Category standard

OSS community · since 2020

Widely used

Mockoon · since 2017

• 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.

• 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.

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

• 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.

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

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