JSON Formatter and Validator
Turn compact or messy JSON into readable, validated output, or minify it for transport.
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About this tool
JSON Formatter and Validator — The formatter parses your JSON before producing output, so malformed quotes, commas, brackets, or values are caught instead of silently copied.
Use formatted output while debugging and minified output when you need a smaller payload. The transformation runs locally in your browser.
How to use it
- Paste a JSON object or array.
- Choose Format for indentation or Minify to remove unnecessary whitespace.
- Review any validation message, then copy the result.
Example
{"user":{"name":"Mona","active":true},"roles":["editor","reviewer"]}{
"user": {
"name": "Mona",
"active": true
},
"roles": [
"editor",
"reviewer"
]
}Formatting preserves valid values; it does not repair ambiguous or incomplete data.
Common uses
- Inspect API responses and webhook payloads.
- Clean configuration files before review.
- Minify JSON for examples, logs, or transmission.
What to know
- JSON does not allow comments, trailing commas, or single-quoted strings.
- A syntactically valid document can still contain incorrect business data.
Privacy: All parsing and formatting happen locally in your browser.
Frequently Asked Questions
Does formatting change JSON values?+
No. Valid formatting only changes whitespace and indentation, not keys, strings, numbers, booleans, arrays, or objects.
Why is my JSON invalid?+
Common causes are trailing commas, single quotes, comments, missing quotes around keys, or unmatched brackets.
Is private API data uploaded?+
No. Formatting and validation run in your browser.