Create mock APIs in seconds
Best Tools For Service Virtualization
Browse 8 + Service Virtualization Tools

Mockoon

Mock Service Worker
Mock API by intercepting requests on the network level. Seamlessly reuse the same mock definition for testing, development, and debugging.
Mocks Server
Node.js mock server running live, interactive mocks in place of real APIs

Mokku
Mock API calls seamlessly

Dummy
Run mock server based off an API contract with one command

OC Mock
mock object testing framework that can be used to create stubs in iOS apps.

Moq
The most popular and friendly mocking framework for .NET

Mountebank
Over the wire test doubles