JSON Schema Validator
Paste a JSON Schema and a JSON document to validate them. All errors shown with field path, message, and failing keyword. Draft-07 via AJV.
JSON Schema Validator is coming soon. In the meantime, try the JSON → CSV converter, which has flattening built in.
How it works
AJV compiles the schema client-side
AJV (Another JSON Validator) is loaded in the browser. It compiles your schema on every keystroke and validates the data document, returning all errors with their dataPath (field location), message, and the failing keyword.
All errors shown at once
Unlike some validators that stop at the first error, AJV's allErrors mode collects every validation failure in a single pass. You see all problems at once, not just the first one.
Example
Validating a user registration payload against a strict schema
{ "id": "not-a-number", "name": "", "age": 200 }3 errors: .id — must be integer .name — must NOT have fewer than 1 characters .age — must be <= 150
All three errors are shown simultaneously. Fix them all before re-validating.
Frequently asked questions
What JSON Schema draft is supported?
Draft-07, the most widely adopted version. It covers type, required, properties, additionalProperties, enum, minimum/maximum, pattern, items, and $ref.
What does additionalProperties: false do?
It rejects any object property not listed in the 'properties' keyword. Without it, extra fields are silently allowed. Use it for strict contracts where unexpected fields should fail validation.
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