JSON Validator

Validate JSON syntax and structure with detailed error reporting

JSON Input

Valid JSON

Your JSON is properly formatted

Sample Data

Features

JSON Validation

  • • Real-time syntax validation
  • • Detailed error messages with line numbers
  • • Support for comments and trailing commas
  • • Duplicate key detection

Schema Validation

  • • Validate JSON against JSON Schema
  • • Type checking and required fields
  • • Nested object and array validation
  • • Custom validation rules

How to Use

  1. 1

    Select validation mode

    Choose between basic JSON validation or JSON Schema validation. Schema validation allows you to verify data structure and types.

  2. 2

    Configure options

    Enable strict mode for additional checks, allow comments for JSON5 support, or trailing commas for lenient parsing.

  3. 3

    Enter JSON data

    Paste or type your JSON in the input field. The validator checks syntax in real-time and highlights errors with line numbers.

  4. 4

    Review validation results

    See detailed error messages with line/column positions. Click on errors to jump to the problem location in your JSON.

Frequently Asked Questions

What is JSON Schema validation?

JSON Schema is a vocabulary that allows you to validate the structure of JSON data. It defines the expected format, data types, required fields, and constraints. This helps ensure your JSON data conforms to a specific structure, making it invaluable for API contracts and data validation.

What are common JSON syntax errors?

Common errors include: missing or extra commas, unquoted keys, single quotes instead of double quotes, trailing commas, unclosed brackets or braces, and invalid escape sequences. Our validator detects all these issues and provides specific error locations.

What is the difference between JSON and JSON5?

JSON5 is a superset of JSON that allows comments, trailing commas, single quotes, unquoted keys, and more relaxed number formats. Enable "Allow Comments" and "Allow Trailing Commas" options to validate JSON5-style data.

How do I validate nested JSON structures?

Our validator automatically checks nested objects and arrays at any depth. Error messages include the full path to the problem (e.g., "users[0].address.zipcode"), making it easy to locate issues in complex JSON structures.

Toolest

Your all-in-one calculator toolkit. Simple, fast, and always accessible.

© 2025 Toolest. All rights reserved.