Mock HTTP API Server & Mock Service Online

Build APIs and accelerate API development with instant OpenAPI mock servers.


OpenAPI Mocking

Mocking your API with Stoplight is your API design’s perfect companion. Powered by Prism, the instant mock server routes incoming requests to example responses or dynamically generates examples on the fly based on your OpenAPI v2/v3 document (formerly known as Swagger).

Instant Mock Server

Supercharge any OpenAPI Specification with Stoplight Studio using our online Mock REST API server. Once you have created or imported your OpenAPI document, you have access to an instant mock server, which automatically reloads when your document changes. A mock API and mock HTTP server simulates the behavior of a real API allowing collaboration and feedback on your API design.


With mocking, you can accelerate the development of new APIs. Teams can work in tandem before the API is available through virtualization. Stoplight’s mock servers and mock server online can virtualize internal and external APIs within your platform with dynamic responses generated from your JSON Schema, which can be run locally or hosted with Stoplight (coming soon).

Automatic Request Validation

Validates requests and responses against your OpenAPI document. Simulates real server behavior by automatically validating incoming request headers, query strings, and request bodies against your OpenAPI document.


Need a specific example or a dynamically generated example? No problem! You can customize responses to what fits for your API when mocking with Stoplight.
Ready to mock your API?