MockAPI vs MockServer

MockAPI lets users create REST API endpoints, generate custom data, and operate on it through a RESTful interface. Each project receives a unique base URL shared by its endpoints. Users define resource schemas and field-level generators, including Faker.js functions such as lorem.sentences and datatype.boolean. Relations between resources can be configured, with endpoints generated automatically. Generated resources support GET, POST, PUT, PATCH, and DELETE operations. Listed query capabilities include pagination, sorting, filtering, data generation, and customizable responses, and OpenAPI import is supported. The service is described for prototyping, testing, and learning. Documentation covers projects, resources, data generation, code examples, filtering, pagination, and relations. The Free plan costs nothing for 1 project and 2 resources. Paid monthly access costs $5 a month, and paid annual access costs $35 a year; each paid plan allows 20 projects and 50 resources. Custom endpoints and webhooks are marked coming soon.

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.