JSON Formatter & Validator
Pretty-print, minify, and validate JSON with clear error messages.
Format, validate and minify JSON
This tool turns messy or minified JSON into clean, indented, readable structure, and validates it as you type by showing exactly where and why parsing fails. Minify does the opposite, stripping all whitespace for the smallest payload. It is an everyday tool for anyone working with APIs, config files or data exports.
How to format JSON online
Paste your JSON, click Format to pretty-print it or Minify to compress it, and watch the validity status update live. Copy the result when you are ready.
Frequently asked questions
Does it validate as I type?
Yes. The status line updates live to tell you whether the current input is valid JSON, and shows the parse error if it is not.
Can it handle large files?
It runs in your browser, so very large files depend on your device's memory, but typical API responses and config files are no trouble.