Validation uses Ajv (JSON Schema draft 2020-12) entirely in your browser — nothing is uploaded.
Validate JSON against a JSON Schema online, free. JSON Schema (the 2020-12 draft) is a vocabulary for describing and validating the structure of JSON data — required keys, types, formats and constraints. This validator checks your JSON document against a schema using the Ajv engine and reports each violation with the exact path to the offending value, all in your browser.
It validates JSON data against a JSON Schema and pinpoints every error by JSON path, so you can fix contract mismatches before they reach production. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.
Each validation failure names the exact location in your data (e.g. /user/email) and what rule it broke, so fixes are fast.
Powered by Ajv, the widely used validator, supporting modern keywords: types, required, enum, format, patterns and more.
Both your schema and data are validated locally in your browser; nothing is uploaded, logged, or stored.
Unlimited validation with no account, on desktop and mobile.
Paste your JSON Schema in one box and your JSON data in the other, then validate. The tool reports whether the data conforms and lists every violation with its JSON path.
It targets JSON Schema 2020-12 via the Ajv engine, supporting common keywords like type, required, enum, const, pattern, format, and numeric/length constraints.
Generating a schema infers structure FROM sample JSON; validating checks that a given JSON document conforms TO a schema you already have. This tool does the validation half.
No. Validation runs entirely in your browser; neither your schema nor your data leaves your device.
JSON Schema is permissive by default — properties not listed are allowed unless you set additionalProperties:false, and keys aren't required unless listed in required. Tighten the schema to enforce stricter rules.