← All tools
Developer · Utility

JSON Formatter & Validator

Paste any JSON to format it, validate it, or minify it. Errors point to the exact line and column that's broken.

Formatted JSON

What this tool checks

This validates your JSON against the standard JSON specification: matching brackets and braces, properly quoted keys and strings, no trailing commas, and correctly formatted numbers. When something's wrong, the error message tells you the line and column where the parser got stuck, usually right at, or just after, the actual mistake.

Common JSON mistakes

  • Trailing commas after the last item in an array or object.
  • Using single quotes instead of double quotes for strings and keys.
  • Unquoted object keys.
  • Missing a closing brace } or bracket ].

Frequently asked questions

Why does the error line not match exactly where I think the mistake is?+
JSON parsers report where they failed to continue parsing, which is often the character right after the actual mistake, for example, right after a missing comma. Check just before the reported position too.
Is my JSON uploaded anywhere?+
No, parsing and formatting both happen locally in your browser using JavaScript's built-in JSON parser. Nothing is sent to a server.