JSON Schema Validator

How to use

1. 1Paste your JSON Schema into the left panel (Draft 7 or 2020-12) and the JSON document to validate into the right panel.
2. 2Pick the matching draft. Use 2020-12 for OpenAPI 3.1 and current Ajv; use Draft 7 for older specs.
3. 3Read the result below: a green banner when the document is valid, or a red list of errors with the keyword, JSON Pointer, and message for every failure.
4. 4Turn on Strict format checking when you want unknown format names flagged as errors, or Verbose anyOf errors to see why each branch of an anyOf failed.
5. 5Use Copy errors to paste the full failure list into a pull request or issue, or load the sample schema with the invalid document to see how the report looks.

About this tool

JSON Schema Validator checks a JSON document against a JSON Schema entirely in your browser. Paste the schema on the left and the document on the right, and a full list of failures appears underneath with the JSON Pointer (RFC 6901) for each failing value, the schema path that produced the constraint, the keyword name (type, required, enum, pattern, format, and so on), and a plain-English message explaining what went wrong. The validator supports the two drafts most teams actually write: Draft 7 (still common in older OpenAPI specs and many Ajv setups) and 2020-12 (the current draft used in OpenAPI 3.1 and modern toolchains). Switch between drafts to pick up the prefixItems / contains / dependentRequired forms used in 2020-12 or the tuple items / dependencies forms used in Draft 7. The full keyword set is covered: type, enum, const, minLength, maxLength, pattern, format (date, time, date-time, email, hostname, ipv4, ipv6, uri, uri-reference, uuid, regex), minimum, maximum, exclusiveMinimum, exclusiveMaximum, multipleOf, items, prefixItems, additionalItems, minItems, maxItems, uniqueItems, contains, minContains, maxContains, properties, patternProperties, additionalProperties, required, propertyNames, minProperties, maxProperties, dependentRequired, dependencies, allOf, anyOf, oneOf, not, and if/then/else. Internal $ref pointers like #/$defs/User are resolved; external refs and dynamic refs are flagged as warnings rather than silently ignored. By default unknown formats are accepted (matching Ajv's default behavior) so you can paste a schema with custom format names without false positives, but a Strict format toggle turns those into errors when you want to enforce them. Verbose anyOf errors include the failures from each rejected branch so you can debug large union schemas. Validation runs locally, so schemas with internal API details, secret patterns, or unreleased document samples never leave your device.

Free to use. Works in your browser. No signup, no login.