Mockoon vs MockWebServer

Mockoon is a free, open-source tool for designing and running mock APIs locally. It supports OpenAPI and can fit into existing applications and API design workflows. Mock behavior can use dynamic templating, rule matching, JSON databases, proxy mode, webhooks, and TLS. The tool can record requests and responses from a real API to create mocks, and it supports proxying and integration testing. The open-source version permits unlimited mock APIs and routes, including parallel runs. Its CLI can run mocks in headless automated environments such as CI, GitHub Actions, and Docker; mocks can also run in serverless environments including AWS Lambda and GCP/Firebase Functions. The desktop app stores mocks locally, works offline without an account, and reports that mock content and request data are not sent to Mockoon. Pro adds real-time team collaboration, synchronized mocks, and deployment management on private infrastructure; it can be self-hosted on-premises, in a private cloud, or on isolated or air-gapped networks. Team is listed at €10 a month, billed annually at €120/license/year, tax excluded. Eligible companies can request one 14-day self-hosted Pro trial with five license slots using a verified work email, without a payment method.

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.