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JSON Schema Validator

Validate JSON data against a JSON Schema definition.

All tools

Schema

Data

Result

OK — data matches schema.

Frequently asked questions

What's the difference between JSON Schema draft 7 and 2020-12?
2020-12 splits validation, application, and meta keywords into separate vocabularies, replaces definitions with $defs, and changes how items and additionalItems behave for arrays. Tooling support varies, so match the draft your library expects.
How do I make a field required in JSON Schema?
Add the property name to the required array on the parent object schema - required is a list of keys, not a flag on the property itself. Listing a key as required only ensures presence; you still need a type or other constraint to validate its value.
Can JSON Schema validate values against an external API or database?
No, JSON Schema is a static, declarative format with no I/O. For dynamic checks like "username is not taken" you need to layer application logic on top of schema validation.