The JSON Formatter and Validator parses JSON locally, reports syntax errors, formats valid JSON with indentation, and creates compact minified output.
How it works
The input is passed to the browser JSON parser. Valid data can be serialized with readable spacing or compact separators. Invalid syntax returns a parser error instead of partial output.
Questions
Does it support JavaScript objects?
No. JSON requires quoted keys, valid JSON values, and no comments or trailing commas.
Is pasted JSON sent to a server?
The calculator is designed for local browser processing. Avoid pasting secrets into any shared environment.
Does formatting change the data?
Formatting changes whitespace only. Parsing and re-serialization may normalize escape or number presentation.
Limitations
Large documents may be limited by browser memory. The tool does not schema-validate fields or repair invalid syntax automatically.