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JSON Formatter

Pretty-print and validate JSON.

100% private Runs locally No sign-up

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Heavy libraries load on demand so the page shell stays fast.

About JSON Formatter

JSON Formatter pretty-prints and validates JSON in your browser — useful when production payloads break and you cannot paste secrets into an online formatter. Indent, spot trailing commas, and copy clean output without a network round-trip.

How to use JSON Formatter

  1. 1Paste or drop JSON into the editor.
  2. 2Format to expand structure, or validate to catch syntax errors.
  3. 3Fix highlighted issues (commas, quotes, brackets).
  4. 4Copy the cleaned JSON back into your app, CI log, or ticket.

Frequently asked questions

Does formatting change data values?

Pretty-printing only changes whitespace. Invalid JSON will not format until syntax is fixed.

Is my API token safe here?

Processing is local. Still avoid pasting production secrets into any shared screen recording or support chat.

Can it minify JSON too?

Use formatting for readability; pair with other dev tools when you need compact single-line payloads for transport.

What about JSON5 or comments?

Standard JSON does not allow comments. Strip comments or convert before formatting.

Large files?

Multi-megabyte JSON can slow the tab. Split payloads or increase available memory if the browser struggles.

Why Toolncy
  • 100% free — no premium tier
  • Files never uploaded to a server
  • Works on desktop and mobile
  • No account or email required
  • Fast local processing in your browser

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