CODING · FREE TOOL
JSON formatter & validator
Validate and format JSON without rounding its number literals or dropping duplicate properties.
Your result
Formatting without rewriting values.
The browser validates JSON syntax, then Toolfred formats the original tokens. Number literals such as 9007199254740993 and 1.2300 are retained exactly. String escapes, property order and duplicate properties are preserved. Formatting does not resolve duplicate keys; other applications may interpret them differently.
Compact mode removes insignificant whitespace. Readable modes insert two or four spaces per nesting level. Output is limited to 8 million characters; split the input or choose compact mode when necessary.