JSON Schema Validator - Free Online Tool

Validate JSON Data Against JSON Schema with Detailed Error Reporting

Professional JSON schema validator to validate JSON data against JSON Schema definitions. Our free online tool provides comprehensive validation with detailed error messages, supports all JSON Schema drafts (Draft 7, 2019-09, 2020-12), and helps you ensure your JSON data conforms to your schema specifications.

Key Features:

Validation Checks:

No registration required. Start validating your JSON against schemas immediately. Our tool provides instant feedback with color-coded validation results and detailed error messages showing exactly where and why validation failed. Perfect for API development, configuration validation, and data quality assurance.

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How to Use JSON Schema Validator - Step by Step Guide

Step 1

Input Your JSON Data

Start by providing your JSON data that you want to validate. Whether you're validating API responses, checking configuration files, or ensuring data quality, you have multiple options:

Paste JSON: Copy and paste your JSON data directly into the top editor
Upload file: Click upload to select a .json or .txt file containing your data
Use sample: Click "Sample" to load example data and schema for testing
Step 2

Provide Your JSON Schema

Enter your JSON Schema that defines the structure and validation rules. The validator supports all JSON Schema specifications:

Draft 7: JSON Schema Draft 7 (most commonly used)
Draft 2019-09 & 2020-12: Newer schema versions with enhanced features
Format validation: Supports email, date-time, uri, uuid, and custom formats
Step 3

Review Validation Results

The validator automatically checks your JSON against the schema and provides instant feedback. Results include detailed error messages:

Valid status: Green checkmark when JSON conforms to schema
Error details: Exact paths, messages, and keywords for each validation failure
Error count: Total number of validation errors found

Step 4: Fix Validation Errors

Use the detailed error messages to fix issues in your JSON data. Each error shows the exact path and reason for failure. You can also format your JSON for better readability or use our JSON validator to check basic syntax first.

Path information: See exactly where in your JSON the error occurred
Error message: Clear explanation of what went wrong
Keyword info: Which schema rule was violated (type, required, format, etc.)

Step 5: Export Validation Report

Save or share your validation results for documentation, testing, or team review. Perfect for RFC-compliant validation workflows:

Download report: Get a detailed text report with all validation results
Copy to clipboard: Quickly copy validation results for documentation
Share with team: Use in code reviews, API testing, or quality assurance

Frequently Asked Questions

What is JSON Schema validation?

JSON Schema validation checks if your JSON data conforms to a predefined schema that specifies the structure, data types, required fields, and validation rules. It's like a contract that ensures your data meets specific requirements before being processed or stored.

Which JSON Schema versions are supported?

Our validator supports all major JSON Schema versions including Draft 7 (most widely used), Draft 2019-09, and Draft 2020-12. The validator automatically detects the schema version from the $schema property or uses Draft 7 as the default.

What types of validation errors does it detect?

The validator detects type mismatches, missing required fields, invalid formats (email, uri, date-time), string length violations, number range errors, array size issues, pattern mismatches, enum violations, and nested object/array validation failures. Each error includes the exact path and detailed explanation.

Can I validate nested objects and arrays?

Yes! The validator handles deeply nested JSON structures including nested objects, arrays of objects, arrays of arrays, and complex mixed structures. Validation errors show the complete path to the problematic field using dot notation and array indices. You can also generate schemas from existing JSON.

Is the JSON Schema validator free to use?

Yes, completely free with no limitations on JSON size, schema complexity, validation frequency, or features. No registration required. Validate unlimited JSON data against schemas with full error reporting and support for all JSON Schema features at no cost.