API Mock Generator
Paste any OpenAPI spec, GraphQL schema, URL or plain English — get realistic mock responses instantly with headers, auth, and error states.
Your mock responses will appear here
Select your input type, paste your API spec or URL, configure options, and click Generate.
Instantly Generate Mock APIs for Faster Development
Frontend developers often wait for backend teams to design and implement API endpoints. With the **API Mock Generator**, you can bootstrap development immediately. Feed the generator an OpenAPI spec, GraphQL schemas, URL endpoints, or a plain English brief, and get realistic mock payloads returned.
Configurable Mock Parameters
Unlike simple static mock servers, our AI-driven engine generates diverse values and edge cases:
- Errors simulation: Generates realistic 400 Bad Request, 401 Unauthorized, 404 Not Found, and 500 Server Errors to test client error boundary code.
- Pagination logic: Returns typical pagination meta formats like cursor/page headers and list wrappers.
- Authorization templates: Includes token types (e.g. Bearer JWT) in the mock response headers.
FAQ
How do I import mocks into Postman?
Download the Postman format collection. Open Postman, click Import on the top left, drop the generated JSON file, and your collection is ready with pre-configured request paths and mock body examples.
Does this support complex nested schemas?
Yes. The generator parses complex types, arrays, object properties, and GraphQL nested structures, keeping relations logical.
Is there any limit to the spec file size?
To ensure optimal performance and speed, files up to 200KB are supported. For larger specs, we recommend pasting specific routes or components.