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JSON Formatter

Format, validate and minify JSON with clear error messages.

How to use

  1. Paste your JSON.
  2. Click Format to pretty-print (or Minify to compress).
  3. Copy the result or download it as a .json file.

Frequently asked questions

Is my JSON sent to a server?

No - parsing and formatting run in your browser. API responses and config data stay on your machine.

How do I find errors?

Invalid JSON shows the error with an approximate line number so you can jump straight to the problem.

Make unreadable JSON readable

APIs return JSON as a single dense line - correct for machines, hopeless for humans. Paste it here and get properly indented, syntax-ordered output instantly, with malformed JSON pinpointed by line and character rather than just rejected. Formatting runs locally in your browser: API responses, config files and payloads full of tokens or customer data never leave your machine, which is not true of many popular formatter sites.

Debugging malformed JSON

The errors that break JSON are boringly consistent: a trailing comma after the last item, single quotes instead of double quotes, unquoted keys, a stray line break inside a string, or a truncated response missing its final braces. When parsing fails, the error message here points at the exact offset - jump there and you'll almost always find one of those five culprits. JavaScript object literals are not JSON: if you pasted code, the quotes and unquoted keys are the problem.

Formatting also functions as validation - if it formats, it parses. For a strict yes/no check in a pipeline or a code review, our JSON Validator gives a clean verdict.

Pretty-print vs. minify

Indented JSON is for reading; minified JSON is for shipping. Whitespace can double a large payload's size, so format while you debug, then minify before embedding JSON in production code or committing fixture files - our JSON Minifier reverses the formatting losslessly. Converting between JSON and YAML, CSV or XML? The matching converters are one click away in related tools.

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