What happens if the schema field is blank?
Whitespace-only schema input skips schema parsing and validation, then runs syntax-only validation on the data JSON.
Build and debug
JSON Validator
Use this JSON Validator to validate JSON with syntax, structure, and validation checks. Add JSON Schema when you have it, or leave the schema blank for quick syntax review.
Developer ToolsPublished Mar 12, 2026Last reviewed Mar 12, 2026
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Validate JSON Even Before the Schema Is Ready
When the schema editor is empty or whitespace-only, JSON Validator skips schema parsing and runs a syntax-only pass on the data JSON. That gives you a fast way to check raw payloads without forcing a schema-first workflow.
Run JSON Schema Validation Without Hidden Fetches
When a schema is provided, the validator runs syntax, structure, and validation checks in a fixed order. Remote references, network fetches, custom keywords, and extra format plugins are intentionally out of scope in this version, so the behavior stays predictable.
See Whether the Problem Is the Schema or the Data
Schema problems and data problems are reported separately, so you can tell whether the contract itself needs work or the payload violates an otherwise valid contract. Unknown schema keywords are surfaced as schema errors instead of being silently ignored.
Frequently asked questions
Are remote $ref values supported?
No. JSON Validator supports internal refs only, so remote $ref values are rejected before validation starts.
Does format invalidate data in v1?
No. In this version, format behaves like an annotation and does not invalidate data or schema by itself.
How are unknown schema keywords handled?
Unknown or custom keywords fail schema validation instead of being accepted silently.
How are duplicate keys handled?
JSON Validator follows JSON.parse semantics for both schema and data inputs, so duplicate object keys keep the last parsed value.
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