API Mock Generator
Define a JSON schema with type hints and generate fake REST/JSON responses. Use for frontend development and testing. All in your browser.
Use string, number, boolean, email, name, uuid, date, id as values for auto-generated fake data. Arrays: use [] with a single object template.
Try it with this example
Define a schema: {"name":"string","email":"email"}. Generate mock JSON for frontend testing.
What is this tool?
Frontend development often needs API responses before the backend exists. The API Mock Generator creates fake REST/JSON from a schema. Define your structure with type hints: string, number, boolean, email, uuid, date, etc. The generator produces sample JSON that matches. Use it for prototyping, testing, and demos. Paste a schema or build one in the UI, and get mock data instantly. All generation runs in your browser. No server, no storage.
Define properties and types. For "name": "string" you get a random name-like string. For "email": "email" you get a valid email format. For "id": "uuid" you get a UUID. Arrays of objects work: define one item schema and request multiple. The generator uses sensible defaults for common types. Adjust counts, nest objects, and regenerate until the output fits your needs. Export the JSON for use in Postman, a mock server, or your app's fixtures.
Use it when the API isn't ready and you need something to code against. When writing frontend tests and need deterministic or varied fixtures. When demoing a UI and need realistic data. When defining an API schema and want to see sample responses. Pair it with the API Schema Validator if you're building OpenAI or Anthropic tools—validate the schema, then generate mocks for testing.
Generated data is random and fake. Don't use it for production or with real user data. For development and testing, it's ideal. All processing is client-side. Bookmark it for frontend and API development workflows.
Essential for parallel frontend development.