JSON Formatter & Validator
Beautify, minify, and validate JSON with clear error messages.
🧩Pretty-print, minify, and validate — privately
Paste any JSON to format it readably (proper indentation, one key per line), minify it for transmission, or simply validate it— with the exact parse error when something's broken. API responses and config files often contain sensitive data, which is why everything here runs in your browser and nothing is uploaded.
🧮The rules JSON actually enforces
JSON is stricter than JavaScript: single quotes, a comma after the last item, an unquoted key, or a stray comment each break the whole document. The validator pinpoints the first violation so you fix it instead of hunting.
{'name': 'Asha',} fails twice — single quotes and a trailing comma. Valid: {"name": "Asha"}.💡Format vs minify
- Format for humans: debugging API responses, reading configs, code reviews.
- Minify for machines: smaller payloads to ship or store (whitespace is ~20–40% of pretty JSON).
- Validation before deploying any hand-edited config file saves the classic midnight outage.
- JSON has no comments by design — use a "_comment" key if you must annotate.
💡 Frequently Asked Questions
How do I fix 'Unexpected token' JSON errors?+
Paste the JSON here — the validator reports the first offending position. The usual suspects: single quotes instead of double, a trailing comma after the last item, an unquoted key, or a missing bracket.
Does JSON allow comments?+
No — the specification deliberately excludes them. Formats like JSONC (VS Code settings) allow them, but standard parsers reject any //. Convention: add a "_comment" field instead.
What's the difference between formatting and minifying?+
Formatting adds indentation and line breaks for human reading; minifying strips every non-essential character for smaller size. The data is identical either way.
Is my JSON uploaded anywhere?+
No — parsing, formatting, and minifying all run in your browser via JSON.parse/stringify. Paste API keys and internal payloads without concern.
Why does JSON require double quotes?+
The spec defines strings with double quotes only, keeping parsers simple and interoperable. JavaScript object literals are more lenient — which is exactly why copy-pasted JS often fails JSON validation.