Mockoon vs WireMock

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.

WireMock simulates APIs and software dependencies so teams can test without live services, exercise edge cases, and build dependent features in parallel. It can match requests using URL patterns, headers, query parameters, cookies, and body content, then return templated responses or simulate delays, network faults, and malformed replies. It can also record interactions with real services and replay them during tests.

The project integrates with JUnit and other testing frameworks, with setup paths for Maven, Gradle, Scala SBT, standalone use, and Docker. Its documented capabilities cover HTTP-based protocols and REST, plus WebSockets, webhooks, HTTPS, gRPC, and GraphQL. WireMock Java is available as a standalone JAR, Docker image, experimental Helm chart, and NPM package; WireMock Cloud is another option. The Free plan costs nothing and includes 1,000 calls per month, one user, three mock APIs, and a 10 requests-per-second limit. Free and trial plans stop running mocks after their API quota is exceeded until the next quota cycle.