Generate JSON Schema
Generate JSON Schema from sample JSON instantly
Input JSON
JSON Schema
How to Generate JSON Schema from Sample Data
Turn example JSON into a reusable schema for validation and documentation. Great for APIs, forms, and configs.
Paste Your JSON
Add a representative JSON payload. The generator infers types, arrays, and nested objects.
Generate Schema
Click generate to build a Draft 2020-12 compatible schema instantly.
Copy or Download
Copy the schema or download it as schema.json for your validators and pipelines.
Why Use DevSensei?
What makes DevSensei different from other tools
Smart Type Inference
Automatically derives types for arrays, nested objects, and mixed content.
Draft 2020-12
Outputs modern JSON Schema compatible with popular validators.
Instant Feedback
Get schema output as you edit with optional auto-generate mode.
Frequently Asked Questions
Common questions about this tool
Yes. The generator targets Draft 2020-12, which AJV and other validators support.
Absolutely. Use the generated schema as a starting point and refine constraints as needed.