100% free · no API keys required
Welcome to DataDevJS
Generate realistic, production-ready mock data and dummy JSON arrays for frontend, backend, and API testing. Customize nested schemas, primitive JS types, and semantic presets instantly.
Schema Builder
Define nested object templates with precise JS types and semantic presets.
Smart Generation
Faker-powered presets produce realistic, context-aware test data.
Export Ready
Copy or download JSON arrays for instant use in your projects.