Paste JSON to validate syntax and get clear error messages with line and column hints. No upload, no signup—your data never leaves your device.
The JSON Validator is an essential tool for developers working with JSON data. It provides instant validation, error detection with location information, and automatic fixing of common JSON syntax errors. Perfect for API development, data validation, and debugging JSON structures.
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Simply paste your JSON into the input field. The tool automatically validates it in real-time and shows whether it's valid or invalid. If invalid, it will display the error message and try to identify the location of the error.
The validator detects all common JSON syntax errors including missing quotes, trailing commas, unquoted keys, invalid characters, mismatched brackets, and malformed structures. It also shows the approximate location of errors when possible.
Yes! Click the 'Fix Common Errors' button to automatically fix issues like single quotes (converted to double quotes), trailing commas, unquoted keys, and comments. Note that this may not fix all errors, so always review the result.
Yes! Our JSON validator is 100% free with no registration required, no usage limits, and no hidden fees. You can validate as much JSON as you need for your development work.
No, all JSON validation happens locally in your browser. We don't store, save, or have access to any JSON data you validate. Your privacy is completely protected.
Yes! When your JSON is valid, the tool automatically formats it with proper indentation. You can copy the formatted version or download it as a file.
Trailing commas are not allowed in JSON. The 'Fix Common Errors' button automatically removes trailing commas. Alternatively, manually remove commas that appear after the last item in objects or arrays.
A JSON validator checks if your JSON syntax is correct and identifies errors. A JSON formatter beautifies valid JSON with proper indentation. Our tool does both - it validates and formats valid JSON.
Yes! Simply copy the JSON response from your API and paste it into the validator. The tool will check if it's valid JSON and help you identify any syntax errors.
JSON requires double quotes for strings, not single quotes. The 'Fix Common Errors' button automatically converts single quotes to double quotes. Always use double quotes in JSON strings.
The tool works best with JSON up to a few megabytes. Very large files may cause performance issues. For extremely large files, consider validating them in chunks or using a command-line tool.
The validator follows the official JSON specification (RFC 7159). It validates syntax, structure, and data types according to the standard, ensuring your JSON is compatible with all JSON parsers.