Format, Minify and Validate JSON

Expand compact JSON into readable indentation or remove whitespace to produce one line. Validate syntax and try repairing common extra commas, single quotes and unquoted keys.

Collapsible formatted results will appear on the right

Worked example

Paste {"name":"Alex","roles":["admin","editor"]} and format it to see the object hierarchy. Minify it for use in API parameters.

Understanding settings and results

Formatting uses JavaScript parsing and serialization. Integer keys may be reordered and numbers outside the safe integer range may be rounded; store identifiers as strings.
Automatic repair handles comments outside strings, trailing commas, unambiguous single-quoted strings and unquoted keys. Unreliable repairs remain errors; check the data meaning afterward.

Scope and limitations

JSON does not support comments, trailing commas, NaN or unescaped line breaks.
Very large input uses browser memory and can slow live formatting.

Troubleshooting

At the reported error position, inspect the preceding comma, quotation mark or bracket.
Integers above 9007199254740991 can lose precision during parsing, not just calculations. Store exact identifiers as strings.

Privacy and processing

JSON is parsed locally in the browser and is not sent to this site.