JSON Output Validator
Valid JSON is a start. Check whether the fields, values and structure match the contract your next step depends on.
TRY A CONTRACT
Start with something that breaks.
Each example includes an output with deliberate mistakes. Validate it, inspect the errors, then load the matching version.
A known label, a confidence from zero to one, and no extra fields.
Defaults to 2020-12. An explicit draft-07 declaration is also supported. Leave blank to check syntax only.
Paste the JSON itself, without Markdown fences. Editing either side clears the previous result.
What this check covers
Validation uses Ajv with JSON Schema draft-07 or 2020-12 and standard formats such as date, email and URI. It checks numeric bounds, extra properties, alternatives, array rules and local references. Unknown keywords, unknown formats, unresolved references and unsupported drafts produce a schema error.
External references are not fetched. Validation does not coerce types, remove fields or fill defaults. Each editor has a 1,000,000-character limit. A separate browser worker is stopped after 2.5 seconds if a complex schema or pattern takes too long.
A matching schema cannot establish facts, detect every harmful action or grant permission to execute a tool. A confidence between zero and one is only a number in range. It is not a calibrated probability.
JSON Schema 2020-12 ↗ · Ajv documentation ↗ · Inspect the validator ↗