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JSON Validator

Paste any JSON string and instantly check whether it is valid. Get clear error messages that tell you exactly what is wrong. 100% Local

How to Use the JSON Validator

Paste your JSON text into the input box. Click Validate JSON and the result panel shows either Valid JSON or a detailed error message describing the syntax problem and where it occurs.

Common errors this tool catches

• Trailing commas in objects or arrays
• Single-quoted strings (JSON requires double quotes)
• Missing quotes around property names
• Unquoted string values or boolean literals
• Mismatched brackets and braces
• Unexpected tokens or extra data after the JSON

Features

• Instant validation with the native JavaScript JSON parser
• Clear, human-readable error messages
• Checks for the most common JSON syntax mistakes
• No data leaves your browser — fully private
• All processing runs locally in your browser. Your data is not uploaded to any server.

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