JSON Formatter & Validator

Any valid JSON including objects, arrays, nested structures, strings, numbers, booleans, and null values.

The validator parses your JSON and reports the exact line and column number of any syntax errors, making it easy to fix issues.

Format, validate, and minify JSON instantly. Syntax highlighting, error detection with line numbers. 100% in your browser — nothing is uploaded.

Input JSON

Formatted output

How to use

1
Paste your JSON into the left panel. You can paste minified, formatted, or broken JSON.
2
Choose a mode — Format (pretty-print with indentation), Minify (compact single line), or Tree View (collapsible hierarchy).
3
Copy or download the output. If your JSON has errors, the exact line and column number is shown so you can fix it fast.

Does my JSON get sent to a server?

No. All formatting and validation happens in your browser using JavaScript. Your data never leaves your device.

What JSON formats are supported?

Any valid JSON including objects, arrays, deeply nested structures, unicode strings, numbers, booleans, and null values.

Can I format minified JSON?

Yes. Paste any minified JSON and click Format to expand it with proper indentation and syntax highlighting instantly.

How does error detection work?

The validator parses your JSON using the browser's native JSON.parse() and reports the exact line and position of any syntax errors.

What is the tree view?

Tree view renders your JSON as a collapsible hierarchy so you can explore nested structures by clicking to expand or collapse any node.