JSON Schema Generator
Generate JSON schema from JSON payload.
Input JSON
Enter a sample JSON document
JSON Schema
The resulting schema definition
About JSON Schema Generator
The JSON Schema Generator infers a strict JSON Schema (Draft 7) from any given JSON payload. This is essential for generating validation logic, writing API documentation (OpenAPI/Swagger), or strongly typing your payloads.
How to Use
Real-World Examples
Generating Validation for an API Endpoint
Take a raw API request payload and instantly generate the JSON Schema required for your backend validator (like Ajv or express-validator).
{
"username": "admin",
"active": true
}{
"type": "object",
"properties": {
"username": { "type": "string" },
"active": { "type": "boolean" }
}
}Best Practices
- Provide a comprehensive sample JSON payload so the generator can accurately determine if a field is an array, object, or nullable.
- Manually review the generated schema to add constraints like `minLength`, `pattern`, or `required` fields that cannot be inferred from a single sample.
Pro Tips
If you provide an array of objects, the generator will attempt to unify the properties into a single comprehensive object schema.
Frequently Asked Questions
Does it support OpenAPI format?
The generated schema follows standard JSON Schema Draft 7, which is highly compatible with modern OpenAPI (Swagger) 3.0 definitions.
Is my data secure?
Absolutely. All processing is done locally in your browser. Your data is never sent to our servers.
Security & Privacy
Schema inference happens entirely in your browser using AST parsing. Your proprietary API payloads are never uploaded or logged.