Hoverfly vs Mockzilla

Hoverfly Cloud is a hosted API simulation and mocking platform for testing without live API dependencies. It handles HTTP/S services including REST, SOAP, XML, JSON, and GraphQL. Users can capture and replay traffic, generate simulations from OpenAPI specifications, and match requests by methods, headers, parameters, and bodies. Simulations can delay responses, inject faults or errors, and modify replies. A command-line interface supports scripted configuration and testing pipelines. Hoverfly and hoverctl binaries run on macOS, Linux, and Windows, while documentation covers Docker and Kubernetes installation. The underlying Hoverfly framework is open source under Apache 2, has no GUI, and is generally run locally or in a user’s infrastructure. Cloud use cases include performance testing, functional testing, and development.

Mockzilla turns OpenAPI specifications or plain JSON files into hosted mock APIs for frontend work, integration tests, and demos. It generates responses from OpenAPI schemas and can validate requests against the specification. Users can inject latency or errors at service or endpoint level to exercise retry and fallback behavior. A proxy can forward requests to a real backend while supplying mock responses for routes that backend does not serve. Its GitHub Action creates a mock URL for each pull request, updates it on pushes, and cleans it up when the branch is gone. Mockzilla records request status and timing, and supports replaying individual requests or sets of requests. The CLI is MIT-licensed, works offline, and can run on a laptop or in CI; hosted cloud features are optional. The site also lists a GitHub Action and MCP server, with CLI setup instructions for Claude and Gemini. The Free plan is free, but API access is unavailable and request history lasts two hours. Hobby costs $10 a month. Uploaded content must not contain personally identifiable information, real financial data, health records, credentials, or other sensitive data.