ToolNest

🧾 JSON Formatter & Validator

Format JSON online free — beautify with 2 or 4 space indentation, minify, and validate JSON with precise error location. Fast, private, in-browser JSON formatter and validator.

🔒 100% Private — no uploads ⚡ Instant — works offline 💸 Free forever — no sign-up

How to use the JSON Formatter & Validator

  1. 1 Paste your JSON into the input box.
  2. 2 Click Format (2 or 4 spaces) or Minify.
  3. 3 Errors are reported with their exact position; copy or download the result.

Frequently asked questions

How do I fix "Unexpected token" JSON errors?

Common causes: trailing commas, single quotes instead of double quotes, unquoted keys, or comments (JSON does not allow comments). The validator shows the position where parsing failed so you can fix it quickly.

What is the difference between Format and Minify?

Format adds indentation and line breaks for readability. Minify removes all unnecessary whitespace to make the payload as small as possible for APIs and storage.

Is my JSON data private?

Yes — parsing and formatting run in your browser only. Sensitive API responses and config files never leave your device.

Is there a size limit?

No fixed limit — multi-megabyte JSON files format fine in modern browsers.

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