JSON Formatter & Validator
Beautify, minify and validate JSON instantly in your browser.
About the JSON Formatter & Validator
Working with JSON means constantly switching between compact machine output and readable indented form, and catching the one missing comma that breaks everything. The AlarmDaddy JSON Formatter & Validator does both — pretty-print messy JSON into clean, indented form, or minify it back to a single line, while validating the syntax and pointing out errors.
Paste any JSON. Choose Beautify to indent it for reading, or Minify to strip whitespace for transport. If the JSON is invalid, the tool shows the parser error so you can fix it. Everything runs in your browser, so even sensitive API responses never leave your machine.
How to use this calculator
- 1Paste your JSON into the input box.
- 2Choose Beautify (indent) or Minify (compact).
- 3Read the formatted output, or the error if the JSON is invalid.
- 4Copy the result with one click.
The formula
The tool parses your input with a strict JSON parser. If parsing succeeds, it re-serializes — with two-space indentation for beautify, or zero whitespace for minify. If parsing fails, it surfaces the exact syntax error.