What JSON Schema Validator does
Validate a JSON document against a local JSON Schema with path-specific failures and no payload upload.
Also searched as schema validation, validate against schema, json schema validator, conform, contract check, schema check.
Parse document and schema
Walk constraints with JSON Pointer context
Return all actionable failures
Current validation surface
Types, unions, required/properties, additional properties, arrays, enums, bounds, lengths, patterns, local $ref, allOf, anyOf, oneOf, not, const, and uniqueItems are evaluated.
The report says what it could not check
Any keyword outside that set is listed beside the verdict, because a document called valid is only valid with respect to what was actually evaluated. Remote references are never fetched, so a $ref outside the document is an error rather than a silent skip.
JSON Schema Validator FAQ
Does jsontools.me upload my JSON?
No. The document is parsed and processed by json-buf inside a dedicated WebAssembly worker on your device.
Does it work offline?
Yes. After the application shell and engine have loaded once, the installable PWA keeps the tools available without a network connection.