Short answer: Mockoon is a dedicated, powerful mock designer; Powerduck generates the mock from the contract. The first gives fine manual control and drifts; the second keeps the mock synced to the spec, the tests, and the docs. Choose by whether the mock should be authored or derived.

What Mockoon is best at

Designing a bespoke mock with precise routes, templating, and rules. It is the right tool when you want maximum control over a standalone mock.

What a generated mock is best at

CapabilityMockoonPowerduck
RoutesHand-builtFrom spec
SourceMock fileOpenAPI contract
On changeManualOn save
Other surfacesSeparateShared

The drift problem

A hand-built mock is a separate artifact and diverges when the API changes. A generated mock reflects the contract, so it cannot quietly drift.

The decision rule

Use Mockoon for a bespoke, highly controlled mock. Use Powerduck when the mock should stay synced and share the source with the rest.

This is part of the Powerduck vs Mockoon comparison. Next, read manual vs generated routes.