Developer

JSON Formatter

Free online JSON formatter, validator, and minifier — paste JSON to format with proper indentation, validate syntax, or minify. Runs entirely in your browser.

JSON Formatter is a free online developer tool from FastDailyTools (Format, validate, and minify JSON.). Free online JSON formatter, validator, and minifier — paste JSON to format with proper indentation, validate syntax, or minify. Runs entirely in your browser. It runs entirely in your browser — no sign-up, no account, no email and no upload — and every result can be exported as a dated PDF report.

  • ✔ Price: free, unlimited use, no rate limits
  • ✔ Sign-up: not required
  • ✔ Privacy: all math runs client-side, nothing is uploaded
  • ✔ Export: one-click PDF report (2026 rates)

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How to use JSON Formatter

  1. Paste JSON.
  2. Click Format, Minify, or Validate.
  3. Copy the result.

Frequently asked questions

Is my JSON sent to any server?

No. Everything runs in your browser — your data never leaves your device.

What does 'Invalid JSON' mean?

Usually a missing comma, unquoted key, trailing comma, or unescaped quote. The validator highlights the line for you.

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