JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. It defines the structure, data types, and constraints of your JSON data, making it easier to validate, document, and share data contracts between systems.

Which JSON Schema draft should I use?

For most modern projects, draft-07 is the most widely supported version and a safe default. Use 2020-12 if you need the latest features and your tooling supports it. Choose draft-04 only for legacy systems that require it.

Is my data private? Does it get sent to a server?

Yes, completely private. The JSON Schema Generator runs 100% in your browser. Your JSON data never leaves your device — no server requests, no uploads, no storage.

Does it support nested objects and arrays?

Yes. The generator recursively walks your entire JSON structure, correctly inferring schemas for nested objects, arrays of objects, arrays of primitives, and mixed-type arrays.

What string formats can it detect automatically?

The tool detects email addresses, URIs, date-time strings (ISO 8601), UUIDs, IPv4 addresses, and IPv6 addresses — and adds the appropriate format keyword to the schema automatically.

Free JSON Schema Tool

Generate JSON Schema
From Any JSON

Paste your JSON data and instantly get a valid JSON Schema with smart type inference, format detection, and multiple draft versions. No signup, no API — runs entirely in your browser.

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Smart Type Inference

Automatically detects types, nested objects, arrays, and nullable fields from your JSON structure.

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Format Detection

Identifies common string formats like email, URI, date-time, UUID, and IP addresses.

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Multiple Draft Versions

Generate schemas in draft-04, draft-07, or 2020-12 format with one click.

JSON Input

JSON Schema

0Properties

0Nested Objects

0Arrays

0Formats Detected

Frequently Asked Questions

Everything you need to know about JSON Schema Generator.

Generate JSON SchemaFrom Any JSON

Smart Type Inference

Format Detection

Multiple Draft Versions

Frequently Asked Questions

Generate JSON Schema
From Any JSON