Free JSON Schema Validator API - Draft-07+

Parameters

name	in	type	required	description
`data`	body	json	required	JSON Data
`schema`	body	json	required	JSON Schema

Request

Send your key in the X-API-Key header. More languages and patterns live on the code examples page.

curl -s -X POST "https://apixies.io/api/v1/validate-json-schema" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"data":{"name":"Alice","age":30},"schema":{"type":"object","required":["name"],"properties":{"name":{"type":"string"}}}}'

const res = await fetch("https://apixies.io/api/v1/validate-json-schema", {
  method: "POST",
  headers: {
    "X-API-Key": "YOUR_API_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
      "data": {
          "name": "Alice",
          "age": 30
      },
      "schema": {
          "type": "object",
          "required": [
              "name"
          ],
          "properties": {
              "name": {
                  "type": "string"
              }
          }
      }
  })
});
const data = await res.json();
console.log(data);

$ch = curl_init("https://apixies.io/api/v1/validate-json-schema");
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_HTTPHEADER => [
        "X-API-Key: YOUR_API_KEY",
        "Content-Type: application/json",
    ],
    CURLOPT_POSTFIELDS => '{"data":{"name":"Alice","age":30},"schema":{"type":"object","required":["name"],"properties":{"name":{"type":"string"}}}}',
]);
$data = json_decode(curl_exec($ch), true);
curl_close($ch);

print_r($data);

import requests

res = requests.request(
    "POST",
    "https://apixies.io/api/v1/validate-json-schema",
    json={
        "data": {
            "name": "Alice",
            "age": 30
        },
        "schema": {
            "type": "object",
            "required": [
                "name"
            ],
            "properties": {
                "name": {
                    "type": "string"
                }
            }
        }
    },
    headers={"X-API-Key": "YOUR_API_KEY"},
)
print(res.json())

Response

The result sits under data in the standard envelope. See the response format guide for errors and status codes.

returns

data.valid: True when the data matches the schema.
data.errors: Failure messages, each starting with the JSON path.
data.data: The data you sent, echoed back next to schema.

example response 200

{
    "status": "success",
    "http_code": 200,
    "code": "SUCCESS",
    "message": "JSON Schema validation completed",
    "data": {
        "valid": false,
        "errors": [
            "$: missing required property 'email'",
            "$.age: expected type 'integer', got 'string'"
        ],
        "data": {
            "name": "Alice",
            "age": "30"
        },
        "schema": {
            "type": "object",
            "required": [
                "name",
                "email"
            ],
            "properties": {
                "name": {
                    "type": "string"
                },
                "age": {
                    "type": "integer"
                },
                "email": {
                    "type": "string",
                    "format": "email"
                }
            }
        },
        "validated_at": "2026-09-18T12:00:00+00:00"
    }
}

Authentication and limits

This endpoint needs an API key. Use the sandbox ("try it" above) to test it without registering. See the authentication guide for details.

Standard rate limits apply to this endpoint.

Common use cases

API request validation

Validate incoming API request bodies against JSON Schema definitions. Ensure clients send correctly structured data before processing.

Configuration file validation

Validate JSON configuration files against schemas in CI/CD pipelines. Catch configuration errors before deployment.

Data migration verification

Verify that migrated data conforms to the target system's JSON schema. Catch structural issues before importing.

related endpoints

POST JSON to CSV Convert a JSON array of objects to CSV format POST JWT Decoder Decode a JWT token and extract header, payload, and claims (no signature verification) POST Hash Generator Generate a cryptographic hash (MD5, SHA1, SHA256, SHA512, etc.) from input text

getting started

authentication code examples response format

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