JSON Schema Generator
Paste any JSON and instantly generate a JSON Schema (Draft 7). Infers types, required fields, and nested object schemas.
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What is a JSON Schema?
JSON Schema is a vocabulary that lets you annotate and validate JSON documents. It describes the structure of your JSON data — what fields exist, what types they are, which are required, and what constraints apply. JSON Schema is widely used for API validation, configuration file validation, IDE auto-complete, and documentation generation.
How to generate a JSON Schema
- Paste your JSON object or array into the Input box.
- Choose your schema draft (Draft 7 is the most widely supported).
- Toggle options like "required fields" and "additional properties" to control strictness.
- The generated schema appears instantly. Click Copy or Save.
Which JSON Schema draft should I use?
Draft 7 is the most widely supported by validators, code generators, and tools like Ajv, jsonschema (Python), and editor plugins. Use Draft 2019-09 or 2020-12 if your toolchain specifically supports them.
What does "additionalProperties: false" do?
It makes the schema reject any JSON object that contains properties not listed in the schema. This is useful for strict API validation where unexpected fields should be an error.
Can I generate schemas for nested objects?
Yes. The generator recursively infers schemas for nested objects and arrays, producing a complete nested schema structure.
Is this tool free and private?
Completely free. Your JSON is never sent to a server — all processing happens in your browser.