MockWebServer vs Mockzilla

MockWebServer is a free, open-source Android test library for developers checking HTTP clients. It provides a scriptable local server where tests supply canned responses and inspect requests made during HTTP, HTTPS, or HTTP/2 calls. Recorded requests expose method, path, HTTP version, body, headers, and chunk sizes for verification. Responses can be queued in sequence or generated by a Dispatcher that applies a request-by-request policy. Tests can throttle responses to imitate slow networks, and socket policies can keep connections open, disconnect during request or response bodies, or send no response. The README includes Java and Kotlin examples. The documented dependency is com.squareup.okhttp3:mockwebserver3:5.5.0, available through Maven Central. MockWebServer is licensed under Apache License 2.0 and is intended for internal and basic testing of apps using OkHttp. The project says it is not a full-featured standalone HTTP testing library and is not actively developed for new features; it suggests MockServer when requirements exceed its scope.

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.