MockServer vs Wilma

MockServer is a free, self-hosted tool for mocking and proxying HTTP, HTTPS, and gRPC services during isolated testing. It can verify requests as well as stand in for services. Teams can generate mocks and validate traffic against OpenAPI or Swagger contracts, or import recorded sessions from browser HAR files and Postman collections. Beyond HTTP services, it can mock gRPC, AsyncAPI brokers such as Kafka, MQTT, and AMQP, and OAuth2/OIDC providers. Its protocol coverage includes HTTP/1.1, HTTP/2, HTTPS, SOCKS, and experimental HTTP/3, which uses a separate UDP port. For fault-oriented testing, it can add latency, errors, dropped connections, and malformed responses to mocked or proxied traffic. Deployment options include Docker, an executable JAR, Helm/Kubernetes, Testcontainers, Homebrew, and a JVM-less bundle. A web dashboard displays logs, expectations, and recorded traffic; Prometheus metrics and OpenTelemetry tracing are available for shared environments. Each instance includes an MCP server at /mockserver/mcp. The /mockserver/status and /mockserver/ready probes remain reachable without authentication or authorization.

Wilma is free, GPLv3-or-later software for developing and testing applications that depend on other services. It combines a service stub with an HTTP/HTTPS transparent proxy, allowing teams to capture, decode, save, and forward traffic, including two-way SSL, or generate configured responses. It can operate as a proxy, a stub, or both. JSON files define stub behavior, and configurations can be uploaded or changed through the interface or service while Wilma runs. Real-time interceptors can inspect or modify requests and responses; custom interceptors, condition checkers, and response formatters can be added, including through classes or JAR files. Message Search finds logged request-response pairs. Wilma supports unit, integration, functional, end-to-end, performance, and manual testing. It is available as Docker images, GitHub release ZIP files, or source builds. The application requires JRE 11, while Message Search requires JDK 11. Logging can be controlled and old logs deleted on schedules.