JSON Formatter & Validator
Format, validate, and minify JSON instantly in your browser. Zero data sent to any server.
Mode:
Indent:
Input
0 chars
Output
// Formatted output appears here...
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Your JSON never leaves your device — 100% browser-based
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Real-time validation as you type
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Supports all valid JSON including nested objects and arrays
About JSON Formatter
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format that is easy for humans to read and write. It is widely used in APIs, configuration files, and data storage across web applications.
How to use this tool
Paste your JSON in the Input box. The tool validates it in real time and shows a formatted version on the right. Switch between Prettify (human-readable with indentation) and Minify (compact, no whitespace) modes. Use the Sample button to see an example.
Common JSON errors
Trailing comma after last object key or array element
Missing quotes around property names
Single quotes used instead of double quotes
Unescaped special characters inside strings
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🔒 All calculations happen in your browser — no data is sent to any server. Results are for informational purposes only.