MockServer vs PactFlow

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.

PactFlow is a managed Pact Broker for teams checking integrations in distributed systems through contract testing. It supports consumer-driven testing with Pact and bi-directional testing with OpenAPI. Its AI-augmented testing can generate tests from OpenAPI, traffic data or existing code. Integrations include SwaggerHub Editor and Pact plugins, including gRPC and protobuf; pull-request status checks work with GitHub, GitLab, Bitbucket or other source control tools. A Developer API, CLI tools and Terraform support help automate configuration. PactFlow offers a managed service and an Enterprise on-premises option. Starter is free, allows unlimited users and includes two integrations. Team includes 50 integrations and community support; it costs $115.42 a month with yearly billing, billed yearly as $1,385, or $127 a month with monthly billing. Enterprise includes unlimited integrations, SAML SSO, role-based access management and dedicated support, with price available through sales. PactFlow states customer data and backups are stored in AWS data centres in Sydney, Australia, with encryption at rest and in transit.