What is JSON validation?

JSON validation checks if your JSON data follows the correct syntax rules. Valid JSON must have proper brackets, quotes around keys, no trailing commas, and correct data types. This tool instantly finds and reports any syntax errors.

What are common JSON syntax errors?

Common errors include: missing or extra commas, unquoted keys, single quotes instead of double quotes, trailing commas after the last item, comments (not allowed in JSON), and unescaped special characters in strings.

Can this tool also format JSON?

Yes! Besides validation, this tool can format (pretty-print) your JSON with proper indentation, and minify it by removing all whitespace. Use the Format button for readable output or Minify for the smallest string.

Is my JSON data secure?

Absolutely. All processing happens entirely in your browser. Your JSON data never leaves your device and is never sent to any server. This makes it safe to validate sensitive configuration files and API responses.

What JSON standards does this support?

This tool validates against the standard JSON specification (RFC 8259). It strictly validates proper JSON — no comments, no trailing commas, no single quotes. For JavaScript objects, convert to valid JSON first.

JSON Validator

Vos fichiers ne quittent jamais votre appareil

Validate your JSON data and find syntax errors instantly. Get detailed error messages with line numbers. All processing happens in your browser — your data never leaves your device.

Paste your JSON

Paste your JSON data into the input area

Validate

Click Validate to check for syntax errors

Review results

See validation results with detailed error messages and line numbers if errors are found

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