Hoverfly 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.

Emerging

SpectoLabs · since 2016

Widely used

Mockoon · since 2017

• Capture mode produces a realistic simulation from live traffic with no authoring.
• Latency injection makes it useful for performance and resilience testing too.
• Small footprint — a single Go binary.

• 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.

• Smaller community and slower development than WireMock.
• Proxy configuration in complex networks takes effort.
• Captured simulations need periodic refresh.

• 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.

Teams needing lightweight service virtualisation against real recorded traffic.

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