JSON Formatter & Validator

How this tool works

Paste any JSON into the box and choose Format to pretty-print it with readable indentation, or Minify to strip all whitespace down to the smallest possible size. If the JSON is invalid, the exact error — including the line and column where parsing failed — is shown instead, so you can fix it without guessing.

Common JSON mistakes

JSON is stricter than JavaScript: keys and string values must use double quotes (not single quotes), there can be no trailing comma after the last item in an object or array, and comments aren't allowed at all. These are by far the most common reasons valid-looking JSON fails to parse.

Privacy by design

This tool uses your browser's built-in JSON parser (the same one behind JSON.parse) entirely on your device. Nothing you paste is uploaded, logged, or stored.