JSON Schema Validator
Validate a JSON document against a JSON Schema (useful subset) with precise error paths.
Validate JSON against a schema instantly. Free JSON Schema validator for types, required fields, enums, patterns and ranges.
Calculator Inputs
About Schema Check
Validate a JSON document against a JSON Schema (useful subset) with precise error paths.
Paste the document and the schema. The validator walks both recursively, checking types, required properties, enums, nested objects and arrays, string lengths and patterns, and numeric bounds — reporting every violation with a JSONPath-style location.
This covers the everyday subset (no $ref, anyOf, or format assertions). For full draft compliance use a dedicated library. Everything runs in your browser.
Where it is used
Checking API payloads and configs, testing schema drafts, teaching JSON Schema, and pre-flight CI payloads.
How to use the Schema Check
- JSON Document — enter the value (e.g. {"name": "Ada", "age": 36}).
- JSON Schema (draft subset) — enter the value (e.g. {"type": "object", "required": ["name"]}).
- Calculate — press the Calculate button to see the result instantly above.
Formula
Recursive subset: type, enum, required, properties, items, string/number bounds.
Examples
Example
Frequently Asked Questions
- Why a subset and not full JSON Schema?
- Full draft features ($ref resolution, combinators, formats) need a heavyweight engine. The subset here covers ~90% of real-world validation needs.
- Does key order matter?
- No. Objects compare by key set, so reordered keys validate identically.
- Can it validate arrays of objects?
- Yes — items schemas apply per element with indexed paths like users[2].email in error messages.