JSON Formatter & Validator
Paste JSON below — it is validated as you type, with clear error messages. Beautify or minify with one click.
What does this tool do?
It parses your JSON strictly, then re-serialises it. Beautify adds indentation and line breaks so nested structures become readable; minify strips all whitespace for the smallest possible payload. If your input is invalid, the tool shows the parser's error message — usually pinpointing the exact spot (a missing comma, a trailing comma, or unquoted keys).
Frequently asked questions
Is my JSON sent to a server?
No. Parsing and formatting happen entirely in your browser using the built-in JSON.parse and JSON.stringify. Your data never leaves your device.
Why is my valid JavaScript object rejected?
JSON is stricter than JavaScript: keys must use double quotes, strings must use double quotes, and trailing commas are not allowed. Change {name: 'Ada',} to {"name":"Ada"}.