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JSON Schema Validator

Validate JSON against a JSON Schema (draft 2020-12, 2019-09, 07, 04). Clear error paths, schema checks and format validation, all in your browser.

Runs locally in your browser

Guides

About the JSON Schema validator

JSON Schema describes what a JSON document must look like: which fields are required, their types, allowed values and formats. This validator checks your data against a schema and lists every problem with the exact path ($.users[2].email) and the schema rule that failed. Click an error to jump to it.

What’s supported

  • Drafts 2020-12, 2019-09, draft-07 (and 06) and draft-04. The draft is read from $schema, or you can pick one.
  • All validation keywords: type, required, properties, additionalProperties, enum, const, minimum and maximum, pattern, items and prefixItems, anyOf/oneOf/allOf/not, if/then/else, unevaluatedProperties, and local $refs to $defs or definitions.
  • Formats such as email, date-time, date, uri, uuid, ipv4 and ipv6 are checked. Turn off Validate formats to treat them as annotations only.
  • Schema check first: the schema itself is validated against its official meta-schema, so a typo like "type": "strin" is reported instead of silently accepting everything.

Privacy and limits

Everything runs in your browser, and nothing is uploaded. For the same reason a $ref to a remote URL is never fetched. Copy the referenced schema into $defs and point to it with #/$defs/….

The validator interprets schemas instead of generating code, so it runs under a strict Content Security Policy. Integers larger than 2^53 are compared as floating-point numbers.