JSON Schema Validator
Validate JSON text against a JSON Schema document and inspect structural mismatches, missing required properties, and type errors.
Run tool
The online JSON Schema Validator checks your raw JSON data directly against a supplied JSON Schema structure. You can paste any structured JSON text into the input field alongside your target schema definition. The tool parses both entries and verifies whether the data satisfies the declared structural requirements. It tests standard data formats including text strings, whole numbers, decimal values, structured records, and item lists across nested levels. When evaluating records, it confirms that mandatory keys are present and respects rules that disallow undeclared extra fields. For list items, it validates each entry against the configured item schema. It also evaluates value constraints such as allowed fixed options, minimum and maximum numeric thresholds, and string length boundaries. If either input contains syntax errors or empty values, the validator highlights the specific issue so you can adjust your data structure quickly.
Instructions
- Enter or paste the JSON text payload into the JSON Input area.
- Enter or paste the JSON Schema specification into the Schema field.
- Click the validation button to process both documents.
- Review the validity report and inspect any listed property or type discrepancies.
Examples
- Validate an object {"username": "alex", "age": 25} against a schema requiring a string username and an integer age with a minimum value of 0.
- Check a product list array [{"id": 1, "title": "Desk"}] against a schema requiring array items with positive integer IDs and string titles.
FAQ
What happens if either the data or schema input is left empty?
If either text field is empty or contains only whitespace, the tool marks the verification as invalid and reports that required input is missing.
How are JSON syntax errors handled?
If either the payload or schema contains invalid JSON formatting, the validator reports a parse error describing the syntax problem.
Which basic data constraints are evaluated?
The validator checks data types, required object keys, disallowed extra properties, array item schemas, predefined value choices, numeric minimums and maximums, and string length bounds.