JSON Schema Validator

Validate JSON data against a JSON Schema (Draft-07 subset) and see every violation

JSON Data

JSON Schema

Validation Result

Result

Click Validate to check the JSON data against the schema.

Table of Contents

How do I validate JSON against a schema?

Paste or load your JSON document into JSON Data and your JSON Schema into JSON Schema, then click Validate. If the data doesn't already have a schema, generate one first with our JSON to JSON Schema tool, then edit it to add the constraints you actually want enforced.

Which JSON Schema keywords are supported?

Type: type (including type arrays for nullable fields)
Objects: properties, required, additionalProperties, patternProperties, minProperties, maxProperties
Arrays: items (single schema or tuple), additionalItems, contains, minItems, maxItems, uniqueItems
Strings: minLength, maxLength, pattern, basic format checks (email, date, date-time, uri, uuid, ipv4)
Numbers: minimum, maximum, exclusiveMinimum, exclusiveMaximum, multipleOf
Values: enum, const
Combinators: allOf, anyOf, oneOf, not

What isn't supported?

This validator does not resolve $ref/$defs references, conditional if/then/else schemas, or remote schema fetching. It's built for self-contained schemas covering the keywords listed above — for full Draft 2020-12 spec compliance with references, use a dedicated library like ajv in your own codebase.

How is this different from the JSON Schema generators?

Our JSON to JSON Schema tools go one direction: JSON data in, a schema out, describing the shape of that one example. This validator goes the other way: you supply both a schema (however it was written) and a JSON document, and it tells you exactly where the document violates that schema — the check you'd actually run against new incoming data.