JSON to JSON Schema Generator
Paste sample JSON and get a ready-to-use JSON Schema (Draft-07). Types, nested objects, arrays, required fields and formats like email and date are detected for you.
Runs in your browser — your code is never uploaded. Tip: drop a file on the input box, or press Ctrl + Enter.
How to Generate a JSON Schema
From one JSON example to a full schema in three steps.
Paste Sample JSON
Paste a real example of your data, or upload a .json file.
Choose Options
Mark fields as required, detect formats, or block extra properties.
Copy or Download
Copy the schema or download schema.json and use it in your validator or API docs.
Draft
JSON Schema Draft-07
Detects
email, date, uri, uuid
Merges
All array items
Privacy
Runs in your browser
Works on
Phone & computer
Price
100% free
How Types Are Detected
Each JSON value becomes a schema type.
| JSON value | Schema |
|---|---|
"Asha" | {"type":"string"} |
"[email protected]" | {"type":"string","format":"email"} |
"2024-03-18" | {"type":"string","format":"date"} |
42 / 4.2 | integer / number |
true, null | boolean, null |
[{…},{…}] | array with merged items schema |
| Field missing in some items | Not listed in required |
What Can You Use It For?
Popular ways people use JSON to JSON Schema Generator.
API Validation
Validate requests and responses with Ajv, Zod or OpenAPI.
API Documentation
Describe your data in OpenAPI / Swagger docs.
Form Builders
Generate forms from a schema with tools like JSON Forms.
AI Structured Output
Give an LLM a schema so it returns valid JSON.
Tips for the Best Result
- Use a sample with all possible fields filled in so nothing is missed.
-
For arrays, include several items — fields missing from some items are left out of
required. -
Review the result: add
enum,minimumorpatternrules by hand where needed. - Validate your sample first with the JSON Validator.
Frequently Asked Questions
Quick answers about JSON to JSON Schema Generator.
A JSON document that describes the shape of your data — which fields exist, their types and which are required. It is used to validate JSON automatically.
Draft-07 (http://json-schema.org/draft-07/schema#), which works with Ajv, OpenAPI 3 tools and most validators.
All items are merged into one items schema. If items have different types, the type becomes a list like ["string","null"].
It adds "additionalProperties": false to every object, so data with unknown fields fails validation.
date-time, date, email, uri and uuid.
Yes. Copy the object part (without $schema) into your OpenAPI components.
No. Everything runs in your web browser, so your code and data never leave your device.
Yes — 100% free, with no sign-up and no limits.
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