JSON Mock Data Generator
Define a schema and generate realistic fake JSON data in your browser — perfect for mocking API responses before the backend exists.
What is a JSON mock data generator?
Define the fields you need — a name and a type for each — pick how many records to generate, and get back a realistic fake JSON array instantly. Everything runs in your browser: nothing you type here is sent anywhere.
Common uses
- Building or testing frontend UI before the real API endpoint exists
- Seeding a mock server (json-server, MSW) or Storybook fixtures with structured fake data
- Populating demo tables, lists or forms with realistic placeholder data
- Generating a larger dataset than practical to hand-write, to test pagination or UI performance
FAQ
Does my schema or the generated data leave my browser?
No — values are generated locally with Math.random() and crypto.randomUUID(). Nothing is sent to a server.
Can I generate nested objects or arrays inside a field?
Not in this version — v1 covers flat objects, which is the most common shape for mocking an API response.
How many records can I generate at once?
Up to 1,000 per click — enough for a realistic fixture while staying fast to generate and easy to copy.
What field types are supported?
String, number (with a min/max range), boolean, UUID, email, full name, date, and enum (a custom comma-separated pick list).