JSON Schema Validator

How to Use

1. Paste your JSON Schema on the left and your JSON Data on the right.
2. Select the schema draft (Draft-07 or Draft 2020-12) from the dropdown.
3. Click Validate (or press Ctrl+Enter).
4. If valid, a green message confirms the data matches the schema.
5. If invalid, each error is listed with its JSON path, error message, and additional parameters.

Click Load Example to populate both panels with a sample User schema and matching JSON for a quick demo.

Reading the Error Output

Each validation error shows three things:

• Path — the JSON Pointer to the failing value (e.g. /items/0/price or (root) for the top level).
• Message — a plain-English description from AJV (e.g. must be integer, must have required property ‘name’).
• Parameters — additional context such as the allowed types, minimum value, or pattern that was required.

Common JSON Schema Keywords

• type — restrict to a JSON type: string, number, integer, boolean, array, object, null.
• required — array of property names that must be present in an object.
• properties — define constraints for each named property of an object.
• additionalProperties: false — reject any property not listed in properties.
• minimum / maximum — numeric range constraints.
• minLength / maxLength — string length constraints.
• pattern — validate a string against a regex (e.g. ”^[a-z]+“).
• enum — restrict to a fixed set of values.
• items — define the schema for array elements.

Example Schema

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "required": ["name", "age"],
  "properties": {
    "name":  { "type": "string", "minLength": 1 },
    "age":   { "type": "integer", "minimum": 0 },
    "email": { "type": "string" }
  },
  "additionalProperties": false
}

Valid data: {"name":"Alice","age":30}
Invalid data: {"name":"","age":-1,"extra":true} — would produce three errors.